Would this be a reasonable price?

If the horse needs injections to keep from being sore he has a medical problem that is going to increase as he gets older, Injections are given to horses who suffer from Arthritic conditions just like people and one day soon he will just refuse to jump, Canter, Trot, and then even to walk because he will be in constant pain from being ridden. If I owned this horse and you wanted him I would gladly sell him to you for well under $5000, probably half that, he will need more injections as he ages and he is just 15 so by the time he is 20 he will be retired from riding probably completely lame by then.