Underground Sea

Underground Sea sits in Unlimited Edition, part of the Vintage Era era on Cardboard Assets. Raw spot is $1,209 per the most recent manually verified value, last refreshed Jul 13, 2026.

I'm scoring this a 70/100 — PLAY. The math: $2,363 expected value at PSA Regular tier, less raw cost $1,209, less $25 grading fee, less $12 return shipping, less $313 eBay fee = +$804 net per copy. ROI works out to 67% on the raw cost basis.

PSA Regular tier turnaround runs about 65 days. Annualized for capital velocity, that's roughly +373% APR — useful framing if you're thinking about this as a capital allocation, not a one-shot trade.

Pop is growing modestly — +13% Grade 10s in the last 30 days. Not a saturation alarm, but worth tracking. Honestly, the call gets clearer with another month of pop data.

Sourcing raw: high-end card. Don't buy without seeing high-resolution scans of every edge and the surface. Comp $1,209 is your ceiling — bid below it to leave room for grading risk. Auction houses (PWCC, Goldin) sell raw copies of cards in this range with provenance.

Risk to size: grading is one-way. Grading fees aren't refundable, the round-trip eats 65 days of capital, and the comp data lags real-time market shifts. For comparable plays in the same era, look at Timetwister and Mox Sapphire. Numbers above pull from PSA POP Report, recent eBay sold listings, and live TCGplayer market prices.