beemerphile1- From my recent experience of buying a good used chevy/gmc truck with low miles, these things aren't cheap especially if you are looking for a 4 door, or ext cab AND 4x4. I noticed on some of these trucks I was looking at the mileage did not match the condition of the vehicle at all, and this usually means a service man used it around a complex or it was a jobsite truck that doesn't ever leave site. They have low miles, but are destroyed otherwise! So low miles I found out doesn't necessarily mean good truck.
I also suggest when your looking for used trucks is before you buy the one you want, have a local reputable repair shop put it up on a lift and do an inspection for you. These inspections are fairly cheap and can be well worth it.
When you find the right truck you will be happy you waited for and didn't just pick out first one you come across. I Ended up buying an 07'GMC with 65,000 and glad I passed on many others before I found this immaculate one!
Good luck in your searches.