Word from the wise
I could not tell how much money I wasted on it.
But if you are serious:
1) Guns are usually not fully automatic. That rapid-fire is done through the use of a special kind of trigger (I can't remember the name of it, its been way too long), where the user is rapidly double tapping the trigger with two fingers and an automatic fed hopper. It's actually illegal to fire the guns at fully automatic at most fields. A good beginner hopper can run anywhere from $40-$100, and go as far as over $300 bucks for the really good ones. Just don't use one of the gravity fed ones that you probably rented from your field. A good hopper is pretty much required for competitive play.
2) If you want a good beginner gun, get a Smart Parts Ion. It's pretty much the go to beginner gun, and it's relatively cheap(I use the term relatively lightly, as nothing in paintball is cheap). It's good to really get the basics of how to use a high-level paintball gun, and is very customizable. If you end up finding out you aren't as into the sport as you think, you're also only out $100 or so on the marker (another term for the actual gun, you'll hear it used a lot). Also it really depends on what kind paintball you are playing. Woodsball or re-enactment game-type players would usually recommend you something else with higher range, but I never got into that stuff so I can't help you there. I always played speedball, which is traditionally what you would consider the "professional" level, and about 95% of us all had started out with Ions.
3) The paintballs with solid colors are usually not allowed at most fields unless they have a bring your own paint day (as my local one does every Thursday)or they have a fee to bring your own paint. Usually the stuff sold at the fields (white-fill) is actually a higher quality anyway, but it's also incredibly expensive. I use to go through a box of 2000, which is usually around $60-$70 bucks, in two visits, and I was incredibly conservative. The stuff sold at Wal-Mart and Dicks, stuff like Monster balls or whatever they are called, are actually pretty shitty all things considered. They are much cheaper made, and either never break, which means you have to light up whoever you are shooting to only get a few breaks, or break too often, meaning that your hopper or your barrel will either clog completely, or will fill them with paint, making you lose pretty much all of your velocity.
Man, talking about is making feel nostalgic, but my wallet is also much heavier since I stopped about 2 years ago.
Still, if you have the cash, have fun, because it really is a blast.
