The one i bought was $100, and i already sent it back. you're not going to want to hear this, but IMO if you spend under $250 you're going to get a lemon.
I'd reccomend this one:
LaserMax Unimax universal green rail laser. You should be able to find one on line for a tick under $300.00
This is a good name brand, and should be 100% reliable and long lasting. The one i bought was neither...
I DO love the green though. MUCH more visible in daytime!