Gamestop has started selling retro games starting earlier this year, but last week they added five more retro systems to their marketplace. Initially the systems included nes, snes, gameboy, sega genesis, playstation, n64, and the dreamcast. Recently expanded systems are sega saturn, gameboy color, gameboy advance, xbox, and gamecube. Gamestop's retro marketplace "sells" the platform's games, accessories, and systems.
As far as variety of items available you are still pretty limited. I know a lot of people who rushed and searched for the infamous $200 gamecube component cables (I curiously did too), but they do not have a page for it. As far as games titles go, they don't have nearly all games listed. Only the more popular ones. Which is ok for being a mainly modern distributor. If you are searching for a more obscure game, you can easily find it at a local retro store.
I quote "sells" because it appears almost everything is out of stock. These games are for sale online only, and when I go to view the 25 first games for all systems, only 3 out of the 25 items are in stock.
When it comes to collecting older video games, quality and condition are THE defining factor on making a purchase. The scariest part of buying online from Gamestop is that you have no idea if you are buying a loose disc only, a dirt cart, or if the game is in great condition. There also no way to tell if anything is counterfeit. You could be spending near $100 on a Chrono Trigger only to find out it was a replacement label, or a reproduction cartridge. One good thing is that Gamestop will accept returns if it is damaged, or not authentic.
Much to my amazement I was shocked to see that many of the prices are appropriate, or even cheaper than Ebay. (However so few games in stock.) A nice bonus is every game will have a 5% since it is a pre-owned game, if you are a Gamestop Pro member. Perhaps the best deal I saw was Fire Emblem: Path of Radiance (in stock) for $76 while it is sold and traded for close to $100. (sold the next day.)
I should also mention that Gamestop does have a trade in program where you can trade in games for credit and apply this towards these older retro games. This is a good opportunity for anybody with newer games that they would want to get rid of and trade in for the better retrogames.
It's great that Gamestop is recognizing the demand for retro games. Although I honestly do not see this becoming too popular of an outlet for the classic gamers. They have near nothing in stock, and do not have the ability to communicate the condition of the actual item you receive. These negative factors really just don't justify going to Gamestop first when there are plenty of better online retailers, who will even have pictures of the specific item. Gamestop Retro may be a better opportunity for players actually interested in playing older games rather than collecting.