Also, guys, you can scam the system a little.
If the game is MARKED DOWN from an existing price (Rarer and rarer, but still happens), if you scan it, it counts as the original price in the B2G1 calculations, so make sure it's NOT third and it won't get marked as free.
IE:
Doom - $25 (VISIBLY Marked down from $50)
Wolfenstein - $50
X-Men - $50
In THAT order, X-Men would be free, and you pay $75.