Hi, I only know of a couple of folks who truly wholesale games but they both sale on ebay in addition to their sites.
To me this would indicate that it would be hard to compete with them. However if you are looking to resell individual games, they do offer some good lots, from 50 to about 1000 game lots. I have seen them go for as low a 8-10 dollars for the older games..
The best one I know is called 'rhonna24' and her ebay store is called 'the gamers corner'. She sales a ton of games in normally 300-400 game lots. But she also sells in smaller lots also. Most all of the people that I know that sell individual games buy her lots to resell...