Victor wrote to me from Minneapolis: "I ran across this in my own city, and as a Prince fan I thought you would be interested." It's a Yellow 'Cloud Guitar', apparently "made for and used by Prince", selling for $18,750.
Then I found this - the 1,700 word 'Cloud Guitar FAQ', which tells you everything you could ever want to know about these things. The first was "built in 1983 by David Husain Rusan, luthier at Knut Koupee music store in Minneapolis", four were built and resprayed various times. It seems that one of them is at the Smithsonian. Then, "During the Diamonds & Pearls era several Yellow Clouds were built to be sold at the Minneapolis & London NPG shops". These are what you'll see at your local Hard Rock Cafe, apparently built by Prince’s guitar tech at the time (I suspect this is what's going for $18k). During the NPG era, Schecter were contracted to build replicas (with dot position markers, rather than symbols) for sale at gigs and through his website. Of course, you can make one yourself, or buy a tiny one, although I can't really understand why anyone would want to...