$8,150: Genius or Idiot?

51 bidders competed for a PSA 10 Mewtwo GX and the winner still paid 0.89x the median of 16 matched sales.

A 2017 Shining Legends Mewtwo GX Secret Rare Holo in a PSA 10 holder closed at $8,150 on eBay on September 7 after 51 bids. The matched-comp median for the same card at the same grade is $9,107.50, which scores this buy 81 of 100 and lands it in GENIUS territory.

Why it matters

The buyer paid under the card’s own comparable median, which is the definition of a good fill and the heaviest single input in this model. Comp deviation scores 36 of 40 and carries most of the weight.

By the numbers

• 0.89x — what the winner paid against a matched-comp median of $9,107.50, computed from 16 matched sales of the same card at the same grade.
• $957.50 — how far under that median this sale closed, with the middle of the pool sitting between $8,600 and $9,300.
• 51 bids — a genuinely contested auction, which is why price discovery scores 15 of 15.

The intrigue

A contested auction that finishes below the comparable median is the unusual case. 51 bidders pushed this one and it still settled under where the same card in the same holder has been trading, so the discount was not one quiet buyer catching a sleepy listing. The market set this number, and it set it low.

Reality check

The pool is 16 sales, above the floor but not deep, and it runs $5,230.35 to $11,100 — a 2.12x span against a 1.08x interquartile ratio, so the tails are far wider than the middle. Liquidity scores 9 of 15 on that depth. The trend also points the wrong way: -3.9% over the 6 most recent sales against the full window, so the benchmark is drifting down. And the card’s 78/73 is a secret-rare set position, not a stated run size, so scarcity 12 of 15 rests on the PSA 10 grade rather than on any applied numbering.

What's next

The full breakdown: comp deviation 36 of 40, trend 9 of 15, liquidity 9 of 15, price discovery 15 of 15, scarcity 12 of 15. That totals 81 of 100 and the verdict is GENIUS, with no cap applied. Watch whether the benchmark holds: it has already softened -3.9% inside the window, and one more leg down turns a 0.89x fill into a flat one.

How we track this

RazMania monitors completed eBay sales daily and drops multi-card lots, reprints, altered slabs and best-offer listings, where eBay publishes the seller’s asking price rather than the figure actually paid. This verdict rests on one narrow query for the same card at the same grade: 16 matched sales, median $9,107.50, interquartile ratio 1.08x, with the lead sale excluded from its own pool. The score has no population report, no sell-through data and no card-level search volume behind it. It is a read on one verified sale, not a ranking of the day.