Shuddering from 50-65. . .??

Anybody know what might be causing this? There is a lot of shuddering in the steering wheel between 50-65 mph. Below and above that range, it is fine. I am hearing different stories from different dealerships:
1. bent front wheel causing it (and it is a minor bend, so i know this is not the issue; i've bent wheels much worse than this before, and it has not effected driveability)
2. shock towers are shot
3. axle boot is leaking, so there might be an issue with the axle

any ideas? also, what kind of cost am i looking at if this is indeed an axle issue?

Could be that bend in the wheel, wheel balancing, or the wheel hub.