His temperament is rated at a 6, which means he's not going to be very laid back. Probably won't do well at just being a pleasure mount.
I could be wrong, but he sure as heck doesn't look to be anywhere close to 17.2 h. Methinks someone's fudging his height just a tad.
He's a coming 5 y/o and has done exactly nothing except race 3 times, and they want $3,500 for him? I think someone's dreaming!
If you want an ex-racer who needs to be retrained, you can get one for a LOT less than $3,500, who has a nice, calm disposition. I'd pass.