I am thinking about getting a laser for a rifle, and maybe for a pistol. I don't know anything about them other than that green is supposedly better than red. I have read that some of the really cheap ones, usually from China, might be underpowered or under-focused? I seem to see 5 mw listed as output, if it even lists the output. Whats a good baseline for cost versus performance for either rifle use or pistol use? Thanks for your help!