This isn't an "AMAZING" deal, but Amazon currently dropped the price for Cave Story 3D by $10, down to $29.99. This isn't amazing because it seems like the basement for price cuts for 3DS games, 6 months after release, seems to be around $20, give or take (Excluding post-launch 1st party, of course)
BUT Cave Story 3D has been stubborn. EXTREMELY STUBBORN. This is the first price cut I've seen for this game, and I don't know if it'll go lower. It may. It may not.
I've heard less than stellar things about this version, so I'm going to wait. But just thought I'd mention it to interested parties.