Freind of mine leases/rents Bulls, $50 per cow you own, you get the bull for three heat cycles about 70 to 75 days. It works great for him and for the person leasing the bull. He doesn't feed the bull but for a couple of months a year and the person leasing the bull only has to feed a bull for a few weeks.
I have thought about buying a bull at the sale, having them test him, take him home for 90 days and then run him back through the sale...... I have just a few head these days, in the rebuilding stage.