lasermax lasers replace the guide rod, and the slide takedown switch on the frame operates the laser from either side.
its a push on/off arrangement.
nobody makes a cheaper guide rod laser, if you want a quality piece of miniaturization, you have to pay for the quality.
as per your question for the "handle mounted" laser in the other green laser thread, I think Crimson Trace is the only maker of the laser that goes on the actual grip of the gun, the laser will then sight down the side of the glock, as opposed to under or inside.
Crimson trace is also a quality maker, for whom you pay quality prices.
the only "cheap" options for a pistol laser are the under rail mounts, if you want good stuff, you pretty much have to pay the price for it.
Also, see the post I made about the laserlyte module for rail mounting, its the smallest rail mounted laser module i've ever seen.
http://www.pafoa.org/forum/optics-46...le-review.html