Asking ppl who knows a lot about pokemon card. I'm planning on selling some of mine and wondering how much the diamond rarity cards are worth.
Just search for it on whatever website sells random crap in your area. Like Amazon or whatever. Too many factors involved, like edition, misprints etc.
Look on the app store for TCGplayer. I use it for MTG card prices and has preformed nicely. Otoh i dont play or collect pokemon so ymmv.