I have owned two OTTB's and they were both hard keepers. That is more of a problem if you board bc others will complain that you don't feed your horse.
Almost ALL TB's on the market are OTTB's (Off the Track Thoroughbreds.) Track trainers see little need in many ground manners, and sell them off before they are trained to:
1) tie to a post
3) give to the bit
4) listen to walk and trot and canter cues
Hunter/Jumper ppl like to buy and retrain them bc many are scopey. Why should you care?
BC they HAVE been trained to run fast, in a straight line, as if a predator was chasing them.
expensive TB's are right off of the track bc:
1) Not fast enough to cover their keep$
2) Injured/recovered from an injury and cannot cover their keep$
Sometimes somebody will train one of these well and then resell. If I did that it would be bc the OTTB:
1) Suffers from a permanent, recurring injury and not always sound
2) Cannot handle desensitization training to those noises and objects I would meet trail riding, etc.
(I am retired from CW Reenacting, after 26 years.)