As another poster said, keep your eye on craigslist. I got my trainer from CL, it was about 1/2 of what I'd pay in a store. I've not experienced any issues with it harming my bike but I do use a special tire instead of my regular tire. The special tire is for three reasons, noise (it's a slick), keep from wrecking my good tire, and to keep it cleaner. Trainer tires don't break down as easily against the trainer and thus avoiding black rubber speckling from carpets and walls.