Any ideas on how to make money?

At the moment I keep my two horses on my own property but I hate it. I don't have an arena or trainer or flat area to ride so its very difficult especially when trying to train two horses. They are very nice, expensive horses that are wasting away because I'm not showing them at all. I'm trying to move them to a boarding barn and I found the perfect one. Its the top Hunter/Jumper barn in Knoxville, so its veryyyy expensive. It would be $2200 a month for both my horses and that includes 3 lessons a week. My family is NOT rich at all so there's no way this could happen. I emailed them and asked them if I could work some of the board off and they haven't responded but I don't know why I couldn't. But I would need to make money to pay the rest of it. Any ideas on what I can do? I'm 15 so driving a lot is difficult but I think I could make it happen. So ideas would be awesome, because I really want to make this happen. Thanks!