for the frame or the whole bike? A good Ti hardtail frame will be close to $2K. For a hardtail I'd go either steel or Ti. I despise aluminum for anything except full suspension. And I'm not a fan of full suspension, so I guess I really don't like Al
I agree with the small builders. Soulcraft are some of the guys that used to be with Ross Shafer at Salsa before he sold the brand name to QBP. There are tons of great steel frames from small builders. For the money, I think Curtlo is one of the best (
www.curtlo.com). Doug does great work. But Sycip, Steelman, Titus, IF, etc...there are too many to list. I would say figure out how much you want to spend on a frame, figure out a material, and whether you want/need to go custom.
If you decide to go mail order, talk with these guys:
http://www.speedgoat.com
I've known Chris and Beth since they started back 10 years ago or so. They are awesome.