I already picked one of these up from another member, I gave him some wii points I had left over from Pepsi promotion.
I think this was a really great idea. I get the full version of the rock band unplugged (gaming wise), only now I just get the songs I want. I bought mine for the equivalent of $6.00. I still got six songs ("still alive" can be had for free on PSN) of which only one I didnt want, as opposed to the higher price and roughly 20 songs I dont want in the full version.
I would suggets the OP post this in the Trading forum, since people there may be more willing to pay/trade for a code like this. Chances are they just wont see your post in this section fothe forums.