Botach, the shady shippers, have the TRL-2 laser & 135lumen light set up for $200. I have the TRL-1 light and freaking love it. Blade-tech makes an -extremely- sturdy and secure OWB Holster for them too.
I don't use lasers, others may have superior suggestions.
The problem with Botach, you never know if you're going to get it...even if they say it is in stock.
Other people sell it for about $250-$300.
Glock had that weird mag base plate, Scorpion mount. I got 5 of them for a couple bucks years ago.
http://glockstore.com/pgroup_descrip/16_Police+Flashlights/6975_Glock+Flashlight+Adapter/
I have a G23 with I would say in excess of 1500 rounds, no FTF or any issues WSO all with a Laser Max installed.