I'm a zwift user and I really like it. You can designate a course and it will adjust the resistance to match the elevation changes. There is live or ghost racing (with simulated drafting, which is cool) and other neat things, but the routes and structured training is what I'm there for.

My tacx trainer was only $300 or so when I bought it, which was comparable to non-bluetooth trainers. That said, I already owned a fancy roadbike to use with it, which is not a negligible cost.