There's a Kodak 760M on ebay right now. These don't show up very often, and I'm betting it's going to get pretty high. Maybe over five grand? With over nine days left to go it's already jumped up over $1000 dollars.
That seems like a lot for a six megapixel camera that what? ten years old? But, this is one of the very few true monochrome digital cameras ever made. I'd love to have one to play with, but that's just out of my league for a toy.
Update: It went for $2,130.00.