If you like GH/Rock Band, have not purchased them, and own a PS3.
Right now K-mart is having a fire sale on this stuff. PS3 versions of GH3 with wireless guitar, GH Aerosmith with wireless guitar both for 7 bucks out the door. PS3 Rock band with all the instruments is 35. I was able to find a GH3 at my local K-mart here and grabbed an Aerosmith at K-mart one town over. Unfortunately I haven't been able to find a Rock Band.
Anyhow, if a K-mart is near you it may be worth checking out.