I always mount my own as well. Hit the hobby shop on base. Every base I have ever been at has a tire machine. If you don't know how to use it I am sure they'll help you out or show you how. It usually a few bucks per tire at the hobby shop. Way cheaper than having a tire store do it, and plus you'll learn something new

Took them 41/2 hours because the tire sidewalls were compressed because i had them stacked for 5 months lol
. The big tires are pretty easy to get on as they have some pretty big flexy side walls . I tried mounting a low profile 205-40-17 one time and that sucked
. for normal tires it's about $15 each and most shops charge double for any tire over 38" because they use 2 guys as they claim the tires are heavy
(wuss) .