As others have mentioned, don’t think you can guarantee this is a $20+k horse based on the given details. The PPE is probably a gamble and a quoted $4k/yr lease fee leads me to believe we are talking local quality here.
OP would have to be ready to take horse back, keep it in work, probably put it with a trainer, and take their chances on a finicky open market without a lot of cushion in their price. Then pay a commission. And they risk of getting stuck with the horse after all of that.
IOW, I would not be tossing the lease folks to the curb.