IBM z50 laptops are about $100 on eBay. Windows CE, 48 MB RAM, 8" screen, keyboard, the works.
Granted, you have to fold it open like a laptop, but I think things like this BSQUARE device are poor designs. If I'm going to put something down on a table and type on it, I'll either use a foldable keyboard or a laptop.
What I'd like to see is a company that can take an AXIM, and add in the headmounted display and the
Twiddler from Handykey and make a whole package under $500.
Put the Axim on your belt, use the Twiddler in one hand, and the head-mounted display, and you are good to go.
JT$