It sounds like this horse is a long way from being an arena horse for someone else to ride...and pay for the ride. Then you need to consider insurance for liability.
Just consider all the issues before you take this on. Sometimes we want something so badly that it hurts. But it hurts worse to have it and lose it not to mention the hole in the wallet.
If you can handle it, fine. But don't plan on any sort of imcome until way down the road. You need a very well trained horse for that.
Good luck with your decision.