Your best bet is to save up a little more money and get a second hand automag. But it really depends on where your game is going. If you only want to play occasionally then a tippman, spyder or pirhanna would be fine. But if you want to ake it further then go for a mag. Check out ebay or automags.org for some really good deals. Bear in mind that you will need a hopper, Co2 or air system and an after market barrel. These alone can cost nearly your budget. For about $200-250 you can get the whole package second hand if you are lucky.
Good luck mate.