An X-Keys, in case you don't know, is a programmable keypad. It costs about $120. With HotkeyNet you can buy a $15 keypad and do the same things with it.
There's just one catch. You need at least two PCs. You plug the cheap keypad into the second PC and load a hotkey file on that PC for the keypad.
The reason this works is that with HotkeyNet, every PC (no matter if it's a server or client) can send commands to all the others.