The only things you NEED to play are
1:good charger (or else you'll kill your batteries and have to keep buying new ones)
2: at least one good battery (higher MAH and voltage = longer life and more power, the FAQ has a thing on NiMh and NiCd for you too look at)
3: One AEG. at least a kraken or something CYMA will doo you beautifully.(cheaper guns usually come with a cheap battery that will do you good for a little while)
4: at least one hicap mag (buy more later as needed and 1 usually comes with every gun)
5: goggles or even a full face mask.
That's it, if you get age verified and buy everything from the classifieds on here all that should run you about $300-$450, might even find a $300 used TM.