My story is from the perspective of the buyer. About 4 years ago when I was looking for a horse, I found on line what I thought was a good prospect. After several emails back and forth asking questions I was satisfied that I wanted to make an appointment to ride the gelding. I had all my own tack with me. I drove 1 1/2 hours to the woman's home. She kept the gelding out behind her house. She brought him up to the drive, and as I listened to her praise him, I saw that he had been foundered badly. Long hooves, dished, ridges, a very obvious case.
I then said "I see he has been foundered. He is not what I am looking for. Thank you for your time." I smiled at her, said goodbye, said he was a nice looking horse and began to walk back to my car. She started yelling at me that I hadn't given him a chance, that he rode just fine. She got pretty aggressive in her speech so I backed out of the drive and left without further conversation.
Later that day, she started sending me emails, cursing me, calling names, saying that I had wasted her time because I had not asked specifically about founder and berating me for saying "Thanks for wasting my time". I absolutely never said that. I drove a 3 hour round trip and she spent 5 minutes getting the horse out for me to see. When I said "Thanks for your time" she heard "Thanks for wasting my time" somehow. I had to block her emails. Thank goodness she didn't have my phone.
I say this because your buyer's remark about "good luck selling your horse", depending on the tone in which it was said, may not have been her intent. She may have been really disappointed that she couldn't handle the horse. At any rate, sometimes the horse doesn't fit the buyer and the buyer recognizes that immediately. You are better off not having a person come out multiple times for naught.