From the tone of your post you have never actually played Guitar hero for any length of time.
I have played many of the songs numerous times over just because it is fun. My brother has spent an insane amount of time playing the game just to beat it on expert.
If you get friends to play with you the replay value is endless because almoat anyone will at least give it a shot. Once they do, they can instantly become hooked.
Rockband takes this to new extremes because now you can add singing to the party. I mean how many people do you know that like to get drunk and karreokee (msp).
Also there are an insane amount of songs on this, at least 58 in the main game. This doesn't include bonus tracks like they have on GH3.
EA also plans on releasing new songs weekly.
I'd say there is a pretty high replay value in that $170 package, however, I wouldn't buy it myself since I rearly have people over to play it with, besides my brohter and his friends.
