I'm still fairly new around here and I can tell you that what these guys say is the truth!
Sniping is not as exciting as it sounds, I've not tried it myself but we have a Sniper on our team and he spends alot of time waiting for that one good shot.
When trying to figure out a cost, don't just think about an AEG and some camo. Things often overlooked include
-a good charger to keep those batteries working (the charger that come with the AEG are no good)
-extra mags (most AEG's come with one hicap and you'll want to get a handful of midcaps)
-GOOD EYE PROTECTION
-Good boots will save your ankles
-A vest, sling etc to carry your new toy and all the mags.
Just a few extras to take into account..