Personally in this day and age, if they offer AI, I would do AI. You can generally still send the mare to the farm, and they will have their vet handle and breed your mare, confirm that the mare is pregnant, and will have mare care for your mare for a specified amount of time. To me, AI is less "hazardous" for lack of better word. No chance of the mare getting hurt by the stallion, or the stallion being hurt by the mare. It can be a little more work, if you are having your vet do the insemination, you have to figure out how you are going to get the semen, how it is going to be stored if you get frozen, and you have to monitor the mare closely do ultra sounds, and find the optimal time to breed and contact the farm so they can send you semen, generally from what I've heard, you or the vet have to go to the airport to pick up the straw(s). If you have a smaller mare, and you want to breed to a bigger stallion, sometimes stallion owners will not let the smaller mare be covered live if the stallion is significantly bigger, so in that case, AI is the only way you'd be able to breed. The prices all vary based on what stallion you are breeding to, whether or not you send the mare to the farm, how much the stud fees and booking fees are for the stallion you pick. From what I've seen for a good stallion, stud fees can range anywhere from about $600-$2000, and then you have all the vet fees, and the shipping fees for AI on top of that.