Only $6100 plus pwc isn't too bad. That's a lot cheaper than those backpack water jet things we've seen around. I'd maybe be in for one if I had a bigger garage and wife that's less likely to kill me for buying more expensive toys.
http://aquaticaviation.net/flyboards/
And as one of the comments on the video mentioned, it seems these things make you younger and prettier like everyone in the video.