I used to play paintball a lot... even got a very expensive custom-made autococker. In the end though, it wasn't worth the money. It was nice when I was using it... but there was a lot to keep track of to keep it working perfectly. It seemed like I was often playing "marker upkeep" rather than "paintball". Whenever I wasn't playing paintball, it always seemed like my expensive marker was going to waste unused.
If I had to do it again, especially now that I don't play very much, I'd get a nice Tippman instead. Cheap enough I don't feel bad if I don't play at all one summer, quality enough that I don't feel outgunned when I do play.
Also it would be great if I could convince people to play pump. Its really a more fun style of play... more running around and chasing and it brings sniping and aiming back into the game. That and you don't burn through so much ammo (which is why most fields only rent semi-autos, they want you to throw a lot of paint so they make more money), the markers are usually less expensive, and they run fine on cheap CO2. But its hard when you can't find a place to rent pumps and hardly anyone can be convinced to buy a quality pump on their own.