What is the cheepest kind of horse?

The cheapest breed to keep would be a miniature horse. Typically a equine veterinarian and farrier will charge less for their care and they eat far less than a larger horse or pony. However Mini's should never be ridden, not even by very small children, They can pull a cart with a full grown man though. If you are looking for a riding horse that is on the cheaper side to keep, look for one that is known for being an easy keeper. They tend to do well on basic food stuffs and usually don't require any grain or supplemental feed beside hay and or grass.