It depends on where you are located. There is a place in auburn Alabama named southeast equine rescue. They take thoroughbreds from the kill pen and start redoing there training. They are nice horses!
Search “Saving Baby Fund” They rescue horse and sell them :) the founder also has a book. It’s based in a Michigan though, hope that’s close to you! My friend bought a pony from there, and it was very well taken care of during rehabilitation
Depends on where you are located.
Really depends on what you are looking for, If experience allows an ex racehorse has a lot to offer.