Kmart - AC/DC Rock Band Bundle (PS2/PS3) - $69.00
1 x Rock Band guitar
1 x Rock Band drum kit
1 x AC/DC Live game for PS2 or PS3
This is a good price for the complete bundle, would have paid this price for the game alone a while ago, but I'd say you could now get it for about $30.
So works out about $40 for the instruments...