I purchased this laser boresighter in July:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
Cost was $18, shipped. I've used it on all my pistols to check for zero, and adjust the rear sight, or select front sights. What I don't like about it is that on this particular one, there is no lip on the "cartridge" to the extractor cannot grab it when you try and remove it. You kind of have to shake it out. Also, there's no switch, you just insert the three (provided) batteries and screw down the lid at the rear, and it turns on.
It seems to be pretty repeatable, and the laser beam is centered, radially. It is useful for gross adjustments but I found that ammo selection made a bit of a larger difference at the range, in terms of POI, than assuming the laser boresighter was going to predict PoA=PoI. But for a tool to help me get "close", I'd say it was worth $18.
I made mention to my wife that it might be an alternative to going to the range to burn ammo, given the cost these days. Goal would be to use it for Dry Practice. I may give that a whirl myself. I'd just have to remember to glance at the target when the shot broke so I could see where the dot was. I have mixed feelings however of training a lot that way; I don't shoot a dot and I'm not sure I should be really changing focus from the sights to the target and back but who knows.
It is a handy little gizmo, though, that's for sure.