Piranha Eforce..
www.xpaintball.com. ITs like $99 dollars. Then get a 12 ounce CO2, a gravity fed hopper and spend the rest of your money on the best mask you can find. Might want to look for a used mask if your tight on $$$.
Eforce is a great beginner gun. Shoots fast and is uber durable. Very easy to clean and maintain. Just put adorp of oil in the ASA before every tank and oil your o-rigns before every game and you'll be set.
Looks like you've got yourself bitten by the bug.