She doesn't have the powerful hindquarters that I would look for, but her front end looks cute. The only thing that is turning me off is the price. $900 for a cute horse with no problems riding? Something sounds suspiciously too good to be true to me, but maybe I'm just cynical.
Oh, I watched the video attached to the ad. Now I understand why she's $900. You'll have to undo most of what her rider has taught her. She looks like a barely broke horse that has a good disposition not to toss her rider.
I would pass. You can find something better. A lot of horses on the market these days are cheaper than they should be. You can find something with a better hind end. Barrel racers need that rear of theirs to dig into the ground.