I don't plan on buying WoTLK anytime soon and I've seen more than enough of the quest areas in TBC over multiple 70's. It has been a long long time since I've been through the vanilla 60 instances so......
3-4 days leveling in them won't make much of a difference monmey wise but I can level easily to 63ish in them.

I just don't want to hit the hardest of the bunch first, wipe alot, but make the others even more trivial by being too overleveled for them. I want to enjoy the challenge of all 3 of the instances (never saw much of DM anyway) more so than getting to 70. Anyway, just completed the key quest for Scholo, probably hit that one first, idk. lol we'll see.