Very cool! I love bike touring.
My first experience was doing some sort of organized trip across Minnesota w/ my dad and brother when I was ~17. It was great -- they set up food stops along the way, and you camped each night. No idea what it cost, though.
Then in grad school, I biked around Oahu (over 2 days) several times. I then moved to China, where I spent ~30 days biking in Qinghai (on the Tibetan Plateau, but not Tibet). It was awesome. Some of the mountains were pretty intimidating, but once we were up on the plateau it wasn't too bad.
My preferred ride (for commuting as well) is an aluminum MTB w/ no suspension (for weight). I'd like to check out a proper touring bike, though.