After some contemplation, I think I'll sell them for a reasonable price, if I can. I mean, right now, I only play in one game, so I'm not really using them. Even then, I only need my PHB, and then only until July. I'm pretty sure my current DM will want to switch over. I do too, but just really for the sake of having something new. I never used my 3E books much, anyways, and maybe I won't use my 3.5E books a lot either. But I'll have them, and you never know when a game could happen.
If anyone wants to buy my 3E core books >wink wink plug plug<, I'm at least selling the DMG and MM as soon as possible, and the PHB closer to July.