I am liking what I am seeing here

http://www.fentek-ind.com/keypad.htm#kp21psps

Scroll down, they have a 21 key programable numpad for $70, although the key caps are not "re-legendable" . The one that is Programable and re-legendable is $85. Still, I'd just get the X-Key pro over those. Not sure anyone has tried using those for games yet, so no idea how well their programming will work for you.