. . . and if you do any "serious" four wheeling, you probably won't make it over many obstacles without the additional traction that airing down affords you.
Not an argument, but just a tweak here... In my experience with the FJC (both on BFG KOs and now the MickeyThompson Baja MTZs), the main advantage of airing down hasn't necessarily been the difference between getting over/through an obstacle or not (though it has made that difference on a few occasions), but how
I get over/through it.
I've seen other people with the same, exact setup as mine (same year FJC, same tires, everything) still get through some obstacles that I got through when I was aired down and they weren't, but the difference was that, in their case, it took a lot of revving and taking longer runs at things to muscle their way over/through (which often ends up leading to more damage...even if it's just a flesh wound); whereas with mine, since I was aired down, I simply put it in 4lo, and rolled right through, nice and easy, barely touching the gas pedal ...and when I lock the rear diff, at times it's as if the obstacle isn't even there.
You can get a small $20 one that will stash away easily. It probably won't last forever but it should get you through a couple years of wheeling trips. They are nice for topping off the tires when they need it. Also, if you run over a nail it's a lot faster & easier to pull the nail, plug the hole and fill the tire back up than it is to change to the spare.
I would try to discourage anyone from getting a $20 compressor for airing up tires after a trail run. I have one of that kind, but I leave it in the Kia for flat tire repair/fill-ups.
As long as I've been offroading, I haven't even bothered to have anything like that in the vehicle since it would take so long just to air up one tire, let alone all four.
I also have a better (Q Industries) compressor, and that's the one I keep in the rig. However, after moving from the stock size of tire (265/75/16) to a bigger one (285/75/16), my air-up time with this Q Industries one went from ~5 minutes per tire up to ~20 minutes per tire (going from ~15 up to ~35).
When the combined total was ~20 minutes, I figured, 'OK...I'll just put up with it', but when it's ~20 per tire, there's just no way. If I were going to still use that methodology, I would definitely have to do soe research and get a new, much better style of compressor.
After a few years of seeing CO2 in action among my FJ buddies, I finally got a tank. Now, it's less than a minute per tire.
As has already been said (I know, way too many times), you can get air from one of a number of gas stations in and around the Ouray area. As long as you drive really slow (45 or slower), and make sure to keep pulling over to let others go by if you're on the highway, you'll be fine just airing down at the beginning of Summit and up again before you leave town. Echoing again, there are lots of others that will be willing to help you out if you decide to hold off on getting a compressor of your own for now.