We used to have a herd of about 25 goats. I absolutely loved our goats. We had Nubians and Oberhasli purebreds that we raised and showed. Prices for goats depend on what you are wanting. I assume you aren't looking for a show quality goat. You just want a pet?? Then a wether would be a good choice. This is a castrated buck (a buck is a male goat). They are probably the cheapest goat you can buy. I would try and buy from a reputable breeder. At least that way you know that it has been well taken care of. Even people who show goats will sell wethers at very reasonable prices. You can only have so many males in your breeding program and the rest get castrated as youngsters and sold cheap. Definately should be less than 100 dollars. If you have never raised a baby goat before then I would recommend getting one that is weaned. If you can. Bottle feeding is alot of work, and tiny baby goats must be fed as often as human babies. They also will be missing out on a warm body to keep them warm with no mama or adult goats to lay next to. 4-6 months is a decent start (assuming the weather is warm) and the kids will be eating grain and hay no problem. Make sure they have draft free housing or they are likely to get sick in cold weather. They need to be able to get out the rain too. Most goats don't like to be rained on. They run inside right away.
Goats are very social creatures. They are much happier with another goat. They need very strong and tall fencing. They can jump really good, and like to rub their bodies on any and all fencing. So if it isn't sturdy they escape. Beware of your fruit frees and bushes. Goats won't eat just anything, old wives tale. Be careful of dogs, the sweetest ones have been known to down a goat, especially a goat with no horns (breeders disbud the horns so they don't grow a requirement for showing).
If you think you might want goats milk then I would look for a nice young doe from good milking stock. The best bet in this situation is a bred yearling or two year old. You get milk right away (once she kids) and you get babies without having to worry about a stud. But if you go this route make sure you buy from someone that has a good breeding program and good stock. Someone that you can maintain a relationship with as you will have lots of questions about caring for your new mom and babies when they come.
My next best advice is find a very good vet that knows about goats. Not all do. For some reason you always need a good vet at night or on weekends. Your goats life may depend on this vet one day, so find someone who knows what he's going.
Sorry if I sound preachy. I just really love goats and always want them to have the best home possible.
about your question of too much to pay for a goat, lol I'm the wrong person to ask. I've paid 4 figures for a good stud. Choosing a breed is personal preference, all the full size goats are good milkers if that mattters. The nigerian dwarfs are really cute, but they jump really good. Better than a full size goat. Nubians have the highest fat content in their milk and make great cheese.
Our dd was 3 when we got our goats and she loved them. They were great around her, even the bucks. Usually they knock you over because they want to rub on you. I used to go lay down in the stalls in the barn next to goats when I was stressed out. They always made me feel better.
Have fun with them, I really miss mine. We had to move back to the city for DH job.