Trade bait is the way. What you do is get a JBHi-Fi exclusion list. Avoid the games on the exclusion list. I have bought games for as little as $5 or $10 that I have been able to trade in for the 3 for 1 deal at JBHi-Fi.
Harvey Norman has some good clearance games. Gears of War 2 CE only $15. $5 game was Stormrise- buy a couple copies of that game.
Buy three cheap games for under $20 and trade them in or trade in some of your old games in towards the 3 for 1 deal at JB Hi-Fi. Save more dollars on games but may take a bit of time. But well worth it.
Heavy Rain or White Knight Chronicles. Metacritic suggests it is an easy decision. Heavy Rain will be a much better game with 89%. WKC is another broken JRPG- very common this generation. WKC metacritic is in the 60s.