Most horses are THAT thin for a reason and the reason is not that nobody fed them. The thinner a horse gets, the less and less and less energy it has.
Pack on a couple hundred pounds and you stand to get a free trip to the moon.
I disagree. Yes, Cinny, by all means be ready for him to be a real project under saddle but by no means do all (or even most) horses become thin because THEY were the problem.
I like the looks of him. Its good that your looking into a vet check, he does appear to stand funny in the pictures but my gut says that's poor pictures taken of a horse who's walking around... not standing. That and thin horses always look goofy.
Also, I do not see why it would take six months to be able to ride him again and certainly not $5,000-$10,000 to get him there (if we're only talking a foot trim, de-worming, a quick float and then the feed of course)
This Thoroughbred gelding was being neglected by a boarding stable simply because he required more feed than the owners Arabs and the rest of the boarders horses who were Quarter Horses.
A few extra cups of beet pulp doesn't do a whole lot in the Thoroughbred world
The barn owner swore up and down the horse had a problem so the owner gave me her lovely gelding and eight weeks later I had him looking like this, at which time he was re-started under saddle. Similar story for the many horses I've taken after him.
I would say a good weight gaining diet for a OTTB costs $150 a month for me. (Pasture, free choice second cut Timothy/Alfalfa hay, grain, beet pulp, corn oil, flax) Now, with you boarding I have no idea what that will run you.
I think he is lovely and would go for him, personally. BTW nice of you to consider him either way and good luck! Only you know if you are up to a project under saddle and the finances of a second mouth.