Is this what you are talking about?
It's only $1700. The only way that thing is worth it is if you get an NBA contract after using it. If it is at a gym, then I could see you trying it out. But don't go out and buy one.
You can greatly improve your vert for free. Go out to any basketball court, and simply jump at the rim. Over and over. That's it.
When I was in Jr. High school, I was about about '6 tall, which I still am today. My taller friends and I would jump at the rim every day. We'd do it just to see who could hang on the rim. After a while of doing it we were all able to hang on the rim. And pretty soon we were all able to dunk the ball. I think I was 14 the first time I dunked.
About five years ago I was working out at the track at USC, which had a basketball court on the side. One day after my sprint workout I decided to see how high I could jump. I hadn't jumped at a rim in years. I only got my finger tips on the rim. So I decided that after every workout I'd jump at the rim. 10 times off each foot, and 10 times off both feet. Within a month I was hanging on the rim with ease. I was able to take two steps and hang. The problem I had was that I was doing this on asphalt, and in running shoes. That killed my knees. I had to stop working out for a month. So I would say that you should do it in basketball shoes, which have more cushion, and if you can do it inside of a gym on a wood floor. Try to land with your knees bent to lesson the shock.
I recently changed my workout plan, and now I'm jumping at the rim once a week. I'll let you know how it goes. I'm older now (31), and not as athletic as I used to be (but I'm still way more athletic than most people my age, and a whole lot of people younger than me), but I think I'll be able to dunk again.