Never buy trouble, particularly when it comes to horses. You are just setting yourself up for a lot of heartache. The only way I personally would ever consider taking that horse is if he was free and all I wanted was a pasture ornament. I once had a horse that caught her foot in the fence when she was a yearling. Sometimes she was sound and sometimes she limped but we could never use her for anything. Fortunately for her, I had a lot of pasture and she was able to live her life out there. The best advice I or anyone can give you is to find yourself another horse. One that is sound.