I waited for the PS3 version to drop under $20.00 FOREVER! They finally did. Don't know if anyone out there still plays Rockband 3 anymore but if you do this is the best deal I've seen the Keyboard. YMWV, although many stores around here seem to have them in stock. My kid and I love the keyboard, it's been a blast to play Rockband again after such a long layoff. Good luck!
PS3: http://www.gamestop.com/ps3/accessories/ps3-rock-band-3-wireless-keyboard/78041
Xbox: http://www.gamestop.com/xbox-360/accessories/xb360-rock-band-3-wireless-keyboard/78042
Wii: http://www.gamestop.com/wii/accessories/wii-rock-band-3-wireless-keyboard/78040
PS3: http://www.gamestop.com/ps3/accessories/ps3-rock-band-3-wireless-keyboard/78041
Xbox: http://www.gamestop.com/xbox-360/accessories/xb360-rock-band-3-wireless-keyboard/78042
Wii: http://www.gamestop.com/wii/accessories/wii-rock-band-3-wireless-keyboard/78040