I had an idea for photos on an absorbent material. I wanted to market it but haven't sent the images in for a test run yet. I've submitted a patent on it already.
But, most Art, photography or paintings start in the low hundreds unframed. The guy that shot that stuff has probably got several thousand in lighting alone. Plus he has to pay for a studio, film processing, time to deal with it all, etc. So, $300+ seems fair to me.
However, putting those shots on a standard, flat photo does not appeal to me for a sound room. I'll post some pix of what I put together once I have a final product. I was thinking photos of instruments, singers, and places rather than gear, though.
-C