Adafruit's Boarduino is a nice Uno-compatible clone, and inexpensive. It has no USB interface on board, so an FTDI cable or one of these is needed for programming. Makes sense to me not to duplicate that on every board. The Boarduino is open-source, so if a person wanted a bunch (maybe 10) and was willing to get the boards made and buy the parts, I'd bet they could be made for $10 a copy, maybe less.