For what it's worth. I have seen prices from European dealers that range from Euro 800 to Euro 2,400 for the Neil Pryde foils (no that's not a mistake) and Euro 2,000 to Euro 2,600 for the boards. AU prices are a little bit below that.
The boards are in-line with what you'd pay for a similar formula board. The more expensive Neil Pryde foil is apparently so expensive because it's made from 70 layers of carbon.
The design itself is licensed from F4 foils in the US.Have a look at the video below were they explain everything in detail. The foils seem to be fairly advanced in development. I remember seeing a single hand foil trimaran based on a Cat frame back in the early 90s. Apparently it was developed by a company in California. Wouldn't be surprised if that's F4.
I think there will be a bit of development in the boards. All that said at this prince point I think it's squarely aimed at the formula crowd. I can't see Joe average dropping over $4,000 to learn a "new" sport. I would say for this to catch on manufacturers need to look at some sort of rental program arranged through shops so people can get a taste without dropping thousands of dollars. I would love to give it a go but wouldn't spend that sort of money just to see if I like it.