I wanted a range finder to go along side my ATN X-Sight (the range finder inside it is trigonometry based and pants) but did not want to spend £200 - £300 on one.
As most people would do, I searched Amazon and and of course I was vary as to what I may get or the quality of the unit.

I took the plunge, and here are the results.

https://www.youtube.com/watch?v=wrkzvAF1kzo

In short, yes if you find the right unit and source it from your country (for returns) there are some more than adequate units out there for Air Rifling.