There is no need to pick between them, you can pick most of them up cheap used. I just browsed the prices from some resellers from Amazon and added shipping to the cost.
Rockband 1, ~$10
GH3 ~$5.50
GH2 ~$6
GH Aerosmith ~$6
RB AC/DC ~$12
GH World Tour ~$9
GH 5 ~$13
RB 2 ~ $19
Since you'll need...