Hello. I live in a city, without a car, where I'm only able to train on the streets in heavy traffic. An hour or several out there leaves me feeling like I've smoked a pack of cigarettes in a night. I'm interested in purchasing a trainer and using it for at least an hour a day almost every day of the week. Currently I'm in good enough shape to hold about 15mph for several hours. 40-50 mile bike rides are doable. I'm interested in getting to the level of fitness where I can comfortably ride for 120mph or so at higher speeds. Also I own a $500 cannondale so I'd be more inclined to pay $100 for a trainer than $200. So what do you recommend? Thanks.