I ride a Nashbar aluminum frame that I got for $80 bucks (regularly $99 but wait for the 20% offs). It is short and tall, like track frame geometry, with 410mm chainstays. As to stiffnes, I had it on a computerized trainer two weeks back, with Easton EA50 wheels, could put out 309 watts average and 690 watts peak with very little frame flex. The thing is stiff as all get out. That was over 10km course and I absolutely killed myself doing it, but I wanted to compare it to cheap carbon frames.