What is the Slabline Score?

The Slabline Score is a credit-style 0–1000 protection score for a graded trading-card collection, blended from five weighted factors: Insurance (35%), Concentration (25%), Storage (20%), Liquidity (10%), and Provenance (10%). Higher is better; bands run A (≥880) to F (<400).

How does Slabline value my graded cards?

Each card is valued from recent comparable sales for the exact graded card (by certification number and grade), aggregated across eBay, Heritage, Goldin, and PWCC. More comps yield a tighter, higher-confidence value.

Does Slabline sell insurance?

No. Slabline is software that produces broker-ready insurance schedules and risk reports. It is not an insurer, broker, or appraiser and does not provide insurance, financial, or legal advice.

Which cards and categories does Slabline support?

Graded slabs from PSA, BGS, SGC, CGC, and TAG across baseball, basketball, football, soccer, Formula 1 / racing, hockey, Pokémon, Magic, and VeeFriends.

How much does Slabline cost?

There is a free Ledger tier for up to 25 cards. Collector is $99/year (or $9.99/month) and removes the card limit for an unlimited collection. Insured is $149/year (or $14.99/month) and adds broker-ready insurance schedules and a weekly intelligence brief. A Vaulted tier adds connected Hobby Smart Case hardware.

What is the Hobby Smart Case?

A connected travel case (Travel 40, 75, and Pro) with per-slot temperature, humidity, light, and tamper monitoring, plus GPS location and a chain-of-custody log — turning storage risk into live, sensor-verified data. Launching Q4 2026.

How much is a PSA 10 2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231 worth?

A PSA 10 2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231 is worth approximately $173, based on recent comparable sales. Card values fluctuate with the market.

What's the difference between a Grade 9 and a Gem Mint 10 Sea Monster of Theseus?

For the 2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231, a Grade 9 is worth about $89 while a Gem Mint 10 is about $173 — the grade gap is roughly $84.

How does Slabline value the Sea Monster of Theseus card?

Slabline values each graded card from recent comparable sales of the exact card and grade, aggregated across eBay, Heritage, Goldin, and PWCC. More sales yield a tighter, higher-confidence estimate.

How much is a raw (ungraded) 2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231 worth?

A raw (ungraded) 2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231 is worth about $17, based on recent comparable sales. Values move with the market — track it free in Slabline to see the current number.

How much is a PSA 7 2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231 worth?

A PSA 7 2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231 is worth about $10, based on recent comparable sales. Values move with the market — track it free in Slabline to see the current number.

How much is a PSA 8 2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231 worth?

A PSA 8 2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231 is worth about $12, based on recent comparable sales. Values move with the market — track it free in Slabline to see the current number.

How much is a PSA 9 2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231 worth?

A PSA 9 2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231 is worth about $89, based on recent comparable sales. Values move with the market — track it free in Slabline to see the current number.

How much is a PSA 9.5 2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231 worth?

A PSA 9.5 2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231 is worth about $98, based on recent comparable sales. Values move with the market — track it free in Slabline to see the current number.

How much is a PSA 10 2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231 worth?

A PSA 10 2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231 is worth about $173, based on recent comparable sales. Values move with the market — track it free in Slabline to see the current number.

Slabline^™All graded cards →

2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231

Q: How does Slabline value my graded cards?

Each card is valued from recent comparable sales for the exact graded card (by certification number and grade), aggregated across eBay, Heritage, Goldin, and PWCC. More comps yield a tighter, higher-confidence value.

Q: Does Slabline sell insurance?

No. Slabline is software that produces broker-ready insurance schedules and risk reports. It is not an insurer, broker, or appraiser and does not provide insurance, financial, or legal advice.

Q: Which cards and categories does Slabline support?

Graded slabs from PSA, BGS, SGC, CGC, and TAG across baseball, basketball, football, soccer, Formula 1 / racing, hockey, Pokémon, Magic, and VeeFriends.

Q: How much does Slabline cost?

There is a free Ledger tier for up to 25 cards. Collector is $99/year (or $9.99/month) and removes the card limit for an unlimited collection. Insured is $149/year (or $14.99/month) and adds broker-ready insurance schedules and a weekly intelligence brief. A Vaulted tier adds connected Hobby Smart Case hardware.

Q: What is the Hobby Smart Case?

A connected travel case (Travel 40, 75, and Pro) with per-slot temperature, humidity, light, and tamper monitoring, plus GPS location and a chain-of-custody log — turning storage risk into live, sensor-verified data. Launching Q4 2026.

What a PSA 10 is worth — from real comparable sales.

2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231 card

Estimated value · PSA 10

$173

Based on 299 recent comparable sales.

Value by grade

How much the 2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231 is worth at each grade.

Grade	Value
Raw / Ungraded	$17
Grade 7	$10
Grade 8	$12
Grade 9	$89
Grade 9.5	$98
Gem Mint 10	$173

Which grader maximizes value

Gem / 10 by company

A PSA 10 tops the graded market for this card at $173.

PSA$173
BGS$156
CGC$104
SGC$104

Estimates from recent comparable sales. A higher graded-market value doesn’t guarantee the card earns that grade — Pre-Grade it first to judge the odds.

If you had to sell today

Liquidity

Market value

$173

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Quick-sale recovery

≈ $44

25% recovered

A dealer typically pays about 25% of market for a fast, guaranteed sale — the rest is the liquidity gap. An auction or private sale can recover more but takes time and fees. It’s why your Slabline Score weighs liquidity — and why insuring at market matters: a fire-sale recovers far less than the number you’re covered for.

Estimated from dealer buy-vs-sell spreads; actual offers vary by condition and demand.

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Opens the ROI calculator pre-filled with this card's Grade 9 and Gem Mint 10 values.

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Frequently asked

How much is a PSA 10 2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231 worth?: A PSA 10 2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231 is worth approximately $173, based on recent comparable sales. Card values fluctuate with the market.
What's the difference between a Grade 9 and a Gem Mint 10 Sea Monster of Theseus?: For the 2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231, a Grade 9 is worth about $89 while a Gem Mint 10 is about $173 — the grade gap is roughly $84.
How does Slabline value the Sea Monster of Theseus card?: Slabline values each graded card from recent comparable sales of the exact card and grade, aggregated across eBay, Heritage, Goldin, and PWCC. More sales yield a tighter, higher-confidence estimate.
How much is a raw (ungraded) 2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231 worth?: A raw (ungraded) 2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231 is worth about $17, based on recent comparable sales. Values move with the market — track it free in Slabline to see the current number.
How much is a PSA 7 2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231 worth?: A PSA 7 2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231 is worth about $10, based on recent comparable sales. Values move with the market — track it free in Slabline to see the current number.
How much is a PSA 8 2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231 worth?: A PSA 8 2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231 is worth about $12, based on recent comparable sales. Values move with the market — track it free in Slabline to see the current number.
How much is a PSA 9 2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231 worth?: A PSA 9 2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231 is worth about $89, based on recent comparable sales. Values move with the market — track it free in Slabline to see the current number.
How much is a PSA 9.5 2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231 worth?: A PSA 9.5 2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231 is worth about $98, based on recent comparable sales. Values move with the market — track it free in Slabline to see the current number.
How much is a PSA 10 2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231 worth?: A PSA 10 2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231 is worth about $173, based on recent comparable sales. Values move with the market — track it free in Slabline to see the current number.
Which grading company is the 2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231 worth the most in?: A PSA 10 2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231 tops the graded market at about $173. Across companies: PSA 10 $173, BGS 10 $156, CGC 10 $104, SGC 10 $104.
How much would I actually get selling the 2017 Mega-Tin Mega Pack Sea Monster of Theseus #MP17-EN231?: A quick sale to a dealer typically recovers about 25% of market value — roughly $44 on this card's $173 value. An auction or private sale can recover more but takes longer and charges fees. The gap between market value and quick-sale recovery is the card's liquidity risk.

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Own this card? Track its value automatically.

Add it to your free Slabline collection — live valuations, a 0–1000 protection score, and a broker-ready insurance schedule.

See a full Yu-Gi-Oh! collection scored →

Values are informational estimates built from recent comparable sales — not a certified appraisal, insurance, or financial advice. Card values fluctuate; figures are a snapshot and may differ from a realized sale.