How does it work? Is the extra money based on the in store price of the game, or the trade value of the game? --- When life gives you lemons, you take the lemons squirt them in lifes face, steal lifes wallet, and go out and party!
Tiered as in "sell 2/3/4 and you'll earn 10%/20%/30%"?
It's pretty much trade in all of the games you're going to trade in, and depending on how many you trade in, the percentage of it goes up for extra trade in.
So lets say you sell 2 games at 10 a pop.
Because the deal is 2 games=10% extra, you'll be earning an extra 10 percent for the games. Instead of 20 overall, it'll be 22 (if my math is right of course.)
I'm thinking about it now and they do have a deal, occasionally, where it's 10% extra for every game, but that's not a tiered trade in deal. --- http://psnprofiles.com/Sophistocrat This man is a liar people. Just ignore him and move on http://i.imgur.com/JF8gG.jpg