Trade In Value For These Games?????/?

left 4 dead is new i think they might take it if u give them 2 3 bucks extra or u can give them Mercenaries 2 Gears of war1 or battlefeild bad company only 2 not 3 but gears of war pretty old cheap unless people play online battlefield so many people are playing it same as Mercenaries 2 so it could just be sale one of those two or give themone and a couple of bucks or gears of war and one of them