The 7800 was released in 1986…over 25 years ago! Atari released about fifty games for the 7800 and there were also several 3rd party releases. One of the things that has amazed me is that it is still possible to buy brand new games for the 7800. Atari sold about four million 7800 systems and they must have also made millions of games. Many of these can be had, inexpensively, still shrink wrapped, as they just came from the factory. In fact, I paid no more than $15 each for my first few games, but some were as inexpensive as $5. I was also able to pick up some used games on ebay. I have learned to buy games in lots of six or more; large lots often go for as little as $1-2 per cartridge. Of course, at that price, you are just getting cart without the box or manual.
Games like Alien Brigade, Commando, Ikari Warriors, and Midnight Mutants were released toward the end of the 7800’s life cycle and were manufactured in smaller quantities. These command higher prices all the way up to $100 for a shrink wrapped copy. While collectors may want to have complete games with boxes and manuals, all you need to have fun is the cart itself. There are several sites where you can find the manuals for the games, so it is easy to build up a good collection of 7800 games without spending a lot of $$$.
Also, don’t forget that the 7800 plays almost all of the 2600 games. Loose 2600 carts often sell for less than $1 and there were some great games made for the 2600! Games like Demon Attack, Missile Command, Pitfall, and Warlords play great on the 7800 and are as much fun now as they were 30 years ago!