The mana produced by a Powerstone can't be spent to cast a nonartifact spell, but it can be spent on anything else
These prices give us a clue of the initial interest in these cards: Team Rocket's Mewtwo ex (SIR): 56,800 yen ($380.56) Team Rocket's Moltres ex (SIR): 26,800 yen ($179.56) Team Rocket's Crobat ex (SIR): 13,800 yen ($92.46) Team Rocket's Nidoking ex (SIR): 11,800 yen ($79.06) Team Rocket's Mewtwo ex (Gold): 8,180 yen ($54.81) Team Rocket's Giovanni (SIR): 7,480 yen ($50.12) Team Rocket's Ariana (SIR): 5,480 yen ($36.72) Team Rocket's Mewtwo ex (FA): 3,980 yen ($26.67) Team Rocket's Crobat ex (Gold): 2,980 yen ($19.97) Team Rocket's Meowth (IR): 2,780 yen ($18.63) Jamming Tower (Gold): 2,780 yen ($18.63) Team Rocket's Giovanni (FA): 2,380 yen ($15.95) Team Rocket's Moltres ex (FA): 1,680 yen ($11.26) Team Rocket's Proton (FA): 1,380 yen ($9.25) Blaziken (IR): 1,380 yen ($9.25) Anyone could have predicted Mewtwo would take the top spot
I realized this wasn't working and scrapped a lot of it, though some cards still show in the final list, like Tireless Tracker and Bygone Bishop
The sleeves are made in a thick 100 micron quality and are made to last
They can sell for thousands of dollars