These are all things I have been thinking about myself. I have a spanish mustang that is part banker. There are only about 150 to 200 bankers (corolla island) left and her foal would be 63% when bred to a banker stud. The semen (free) and vet costs are not what have me thinking. It is the weaning of the foal and the fact I have never bred a horse before so foaling is new to me. I have a completely separate pasture so that wouldn't be an issue. Its the fact that I currently only have one horse so there would be no way I could keep the foal here during weaning.