Here in Iowa, people mostly fall over laughing if you say that you plan on packing with a goat (especially when they know you have horses). I guess they don't think about the impact on the land, and the difference in ease of transporting the two... but that's a whole, other, thing.
Goats around here run anywhere from $25 for bottle babies of mixed (probably some dwarf) parentage to $80 or more for the same goat as a yearling, depending on weight.
This time of year, I would get to all the close county and state fairs. There are most likely going to be some 4H kids with goats, and there are almost always some who've made pets of theirs. Those are going to be some of the best socialized goats ever. I can remember having 150 lb. sheep that rode the merry-go-round at the fair with us. They were bottle-fed and were real "people" sheep.
Some of those 4H-ers are going to have to part with those goats, and they might be really happy to know they were going to "working" homes, where they would continue to be valued because of all the socializing and training they'd had.
Since I got my goat, I've been doing that, and have found some wonderful goats and people to contact when I'm ready to move in the second goat. The 4H-ers are a great resource. As are the state goat council people. They were amused about packing, but wanted to know all about how it goes.
My goat was a gift, and luckily he's a tall Saanen wether of good conformation. I found him on the farm where I board. He was one of the goats that came in to be butchered, but was so obviously a hand raised pet that no one had the heart. He was in the $80 range, by weight, at 8 months. He would've been more if he'd been one of the boers, since they are the "angus" goats around here.