Honestly I have no idea what the Dark Persian error is worth. You probably have a better idea than I do, Cheryl. Why don't you give me an offer, and I'll let you know what I think of it. Maybe I'll haggle, maybe I won't.
I got rid of a few error cards I have, but I still have "stage 2" combusken, "monster ball" Voltorb, Fossil Zapdos with missing foil, 1st edition Jungle Electrode with Base picture, "sideways fist" Diglet, "d" edition Butterfree, Print bubble missing UF Electabuzz, and print bubble missing "Best" Rocket's Mewtwo. Let me know if you're interested in any, and what you'd consider fair price.