So, there's this 5 year old, unhandled stallion who is the result of an irresponsible breeder. Last fall he was offered for free to whoever wanted to load him up and put some training on him. Several months passed without any interest, and this stud wound up in a kill pen at the auction house -- which of course stirred everyone up into a must-save-him frenzy. It was $400 to bail him out of the kill pen. Finally someone stepped in to pay for him.
Less than a month later, he shows up AGAIN as a horse needing a new home. The person who took him from the kill pen did not advance his training at all -- he is still a stud who isn't even halter broke. His "rescuer" is now asking $500 for him so that other horses can be "rescued". This horse is absolutely positively no better off than he was. He is the same unhandled 5 yr old stud that was being offered for free, now being offered for $500 after being shuffled around a bit. There is absolutely nothing to prevent this stud from returning to his previous predicaments (ie rotting in a field or sitting in a kill pen).
Rescuing a horse takes a huge commitment. If you're going to do it, the least that you can do is be certain that you are willing to commit the massive amounts of time and money that it takes to truly rescue a horse, without the expectation of receiving anything in return save for what might become an incredible riding partner and the respect and admiration that others have for your compassion. In my opinion, a horse has not been truly rescued until it has been given the fullest opportunity to become a useful pleasure or working horse. In the case of this stud, he needs to be gelded and trained trained trained. There is nothing preventing him from becoming a fantastic riding horse -- he just needs someone who will actually rescue him, because he hasn't been rescued yet. He's just been passed along from one place to another.