From what I've been told, the main difference between low-price trainers and higher priced ones is noise and "feel". The lower-end ones apparently can be very loud but often feel more realistic, while the higher-end ones are much quieter, but can feel less realistic as far as resistance. Or so I've been told.

I'm hoping to get one for this winter, and the most important thing I've learned so far is: Like a bike, buying a trainer apparently takes a good bit of research and testing.