I used to be in the Used Video Game selling business just a few years ago. Its a steady business market that is actually rising. As video game prices go up, more people are looking for used video game copies that they can find good deals on. We had extraordinary success with it. The only reason I am no longer in the business is because of personal relations between the three partners (me being one of the three). We all mutually decided to split and two of us sold off our shares to the third guy who still runs it with success today.
Anyway, the point is that it is a steady market, and I have even considered going back into it, but decided to take a turn towards a more personal hobby instead. Like you said, there is almost guaranteed money in it.
I would like to warn you about something however. You are really fighting an uphill battle if you plan on selling NEW video games. This market is monopolized by a few big players and unless you have hundreds of millions of dollars laying around, I wouldn't suggest trying to compete with them. You know these guys, Best Buy, Gamestop, etc. The reason it is so hard to compete is that when people buy games new, they are expecting a lot of stuff in return. The common thing now is that Gamestop and Best Buy will pay millions of dollars to production companies that produce games like Call of Duty, Battlefield, or Skyrim, to get special unlocks, features, and bonuses that can't be purchased anywhere else. These companies are also requiring HUGE quantities to purchase new game titles. The mark up of these titles is minimal too. Most of the $60 games you see only provide you a markup of $10-$15. Plus you will be surprised at how difficult they are to sell. At these small of margins you can't compete on price, and the other guys have so much on you in terms of bonuses, warranties, chain store locations, etc. that finding buyers for new games is tough. Most buyers of new video games now already have preorders at the big stores and have little interest in risking purchases with small new businesses.
I hope this isn't discouraging, I have just been down this road before and gotten burned. After this experience we focused on selling used video games. You have to constantly be looking around for good deals on bulk buys. There is one AMAZING whole seller that we used to work with called BRE Software. I saw them on the list of Video Game suppliers here on SaleHoo and they are good. They offer you competitive prices and a huge selection. We could buy fairly new games from them that even Gamestop sells used for $50-$55 (because they are fairly new) and we could buy them from BRE for $10-$15 each and sell for $30-$40 fairly easily.
Another great buy that we made was a stockpile of 1,800 game discs. I was surprised but this was probably the best purchase we made. They were disc only, no cases or manuals, etc. We paid $2500 for the whole lot with is barely over $1 each. We bought a bunch of DVD cases and got our company name printed on them and sold them as "Disc Only, In Generic Case". They literally sold like hot cakes. We made our money back on the lot within a few days. It was the busiest time of our business because we were working 80 hours each shipping out hundreds of games a day. That lot probably brought us $16,000 - $20,000 in revenue.
The point of that story is that sometimes things aren't what you expect. We had higher profit margins and more sales/ converted customers than we could have ever had with selling new games.
