Also you'll have to check the strength or class of laser product before mounting it on your marker because people you play with might be upset to lose their sight!
not really worth it.......lasers go in a nice straight line, not deflected by wind or gravity or air-resistance. If you can't aim to the range of a marker without a site then might I suggest a seeing eye paintball labrador?
Get the laser sight dude! It will rock!! You get get one with three dots and everyone will think you are the Predator!!! how cool would that be?!?! And you could get thermoptic camouflage and big dreads to complete the effect, and some infra red goggles!