What can I use and where can I get the cheapest way to have an exbal set up?? I need to get set up with one so I can get a little closer on 1st shot hits at extended ranges in different conditions. I shoot a lot at my elevation which is about 600ft, but I also hunt/shoot a lot where the elevation is 3000-6000ft. I also know that temp and pressure plays a big role beyond 600 yards. I know I"m going to have to get a kestrel weather station as well. I'm just not to up to date on the whole exbal thing. I dont need anything extravagant, just something cheap and simple that works for exbal only. I dont need it for anything else. Thanks guys.