I've been using it myself and with clients that I train. It's like no other workout because you have to use every muscle in your body with each exercise.
Yes, it seems ridiculous to pay $150 for the thing, and if you can figure a way to do it more cheaply, go right ahead. I'm not as enterprising and happily paid money for a product that I find to be pretty damn amazing. If you're interested, I'd definitely seek out a professional who can show you how to use it properly and then decide if it's worth it for you.