Mewtwo

Mewtwo (056/172), the Rare from Brilliant Stars, has an estimated ungraded market price of about $0.60. Note: 14 other cards named Mewtwo exist across the sets Riffle tracks, at very different values; check the collector number.

This page covers Mewtwo (056/172), the Rare (about under $1) from Brilliant Stars.

The other versions: #20/165 from Expedition Base Set (Holo Rare, about $350–$460); #144/146 from Legends Awakened (Rare Holo LV.X, about $240–$320); #11/146 from Legends Awakened (Rare Holo, about $105–$140); #9/100 from Majestic Dawn (Rare Holo, about $75–$100); #56/165 from Expedition Base Set (Rare, about $70–$95); #10/102 from Base Set (Rare, about $65–$90); #10/130 from Base Set 2 (Rare, about $60–$80); #29/110 from Legendary Collection (Rare, about $45–$60); #53/113 from Legendary Treasures (Rare, about $21–$28); #51/108 from Evolutions (Rare, about $4–$5); #75/214 from Unbroken Bonds (Rare, about $3–$4); #059/159 from Crown Zenith (Holo Rare, about $3–$4); #150/165 from 151 (Rare, about $2–$3); #059/142 from Stellar Crown (Uncommon, about under $1).

The collector number printed at the bottom of the card is the reliable way to tell them apart.

Ahead after fees: with a 21% PSA 10 gem rate and current graded prices, grading a near-mint Mewtwo (056/172) is estimated to net about $77 more than selling it raw (est.).

Assumes ~$25/card bulk-rate grading (standard service costs more); ignores turnaround time, sub-9 grades, and shipping. A screen, not a promise.

Mewtwo (056/172) is a Rare. PSA has graded 1,478 copies to date, so graded supply is measurable and growing.

Of the 1,478 copies PSA has graded, 21% earned a PSA 10. That's a low gem rate, so flawless copies are genuinely hard to come by. Grade-by-grade population and pop-over-time appear with Riffle premium.