In the hundreds is realistic... $100 is not. If its got laptop level hardware and the latest peripherals, it's going to be aimed at similar prices, probably as much as a current nettop for just the integrated motherboard. Then to suit the form factor you'd probably be adding a SSD - $100 probably won't be seen for years. As a low price for just the board, even with some cut down options, I wouldn't expect much under $200.
Heck, even VIA's larger and less powerful boards with older peripherals can be $100.