Any Strange related tracks on Rockband will not be free, although they haven't said what the lowest price is. I think it would be a lot of fun to play Tech on Rockband, and I'd def pay for it.
I mean, lets say you sell 30.000 average, every album... If every one of those people dl'd your tracks, and you got 30%, that would be a decent sum of money regardless of the price considering you weren't using them anyway.