I live in texas. I want a horse that is between to ages of four and ten, that i can use for trail riding and just riding for fun. I don't want to use the horse for show, and I don't have any particular markings in mind. I want a mare, average weight, 14/15 hands, registered, utd on all shots and all that, and good for a teen. I also want it to be able to walk, trot, and gallop. What can i expect to pay for a horse like this? Also if you know of any good websites with horses for sale, knowing those would be helpful, too.