Initial costs (not sure of the prices though, and I'm sure it varies by area and vet), are getting a breeding soundness exam done on the mare. You need to make sure that the horse doesn't have any uterine infections, I believe that they will also flush the mare, make sure that everything is in order with her ovaries, and that there's nothing visible that may prevent a successful pregnancy. Next comes deciding whether or not you want to do live cover or AI. Live cover you generally leave the mare at the stallions facility, and they'll tease her, and when the time is right, either decided by her actually being receptive to the stallion, or a vet checking to see where she is in her heat cycle, she's then covered. Each place is a bit different. Some will cover a couple of times, some will cover until she's definitely taken. If you are doing AI, then you have to decide either fresh or frozen, fresh is more expensive than frozen, and if doing fresh, you have to have a vet check her several times, see where she is in the heat cycle, and when the optimal time is to do AI, then you have to get a hold of the farm, and get the straws sent. Doing fresh semen, you have a small window within which to get the straws, and inseminate the mare. Doing frozen, you have to find a vet that has the facility to keep frozen straws, and unfreeze them the correct way, and inseminate her at the appropriate time. After she's been inseminated, you then have to do ultrasounds, and make sure that she actually is pregnant, then start the process of regular visits to make sure that everything is going fine. One person I talked to said that she spent I think it was $7,000 total JUST to get her mare pregnant, as her mare kept twinning, so they had to keep retrying, then after she took finally and had just one, it was another 2 or 3k in regular vet visits, feed, care of the mare ect.