The OPAG site has a pamphlet on a series of globes that Sky&Telescope has been working on for a few years. Now that USGS has finished up their set of Galilean satellite basemaps, S&T may put these globes on sale soon, though they are still looking for input on what would be a good price point and are looking to gauge interest. The globes look very nice, and I would certainly pick up the Io globe, but according to the pamphlet, it looks like S&T wants to sell these as a set rather than individually. The globes would also be limited to 9 inches in diameter.
I would certainly pay 100 bucks for a 12 inch diameter Io globe. Not sure about this set.
Link: Globes of the Galilean Satellites [www.lpi.usra.edu]