Since I just upgraded to an iPad2 I am thinking of selling the "old" one (really just 1 months old since Apple gave me a replacement for my original iPad). It's a 64 GB wifi-only model. Looking at Craig's List or Flea-bay, prices for that model seem to run between $500 and $600. Is that realistic? It seems a tad high to me, but if the market really does bear that...? What do you think a realistic offer price should be?