It’s not a price issue. Buyers who don’t want it aren’t going to buy the horse if you lower the price either. It will limit your pool of potential buyers. Depending on the level of horse - fairly significantly. An upper level/advanced horse is more likely to have a buyer who doesn’t mind, or who has a groom handle the horse. A lower level/first horse type, it’s likely an issue for more potential buyers.
I agree with this. Some people just don’t want a horse at any price with bad ground manners. Others don’t care. I think this issue makes your market a little smaller, but a different price probably isn’t going to move people who are nos into the yes column.
I’ve had two recently with some ground quirks. They don’t bother me in terms of my personal interactions with the horses, but I did feel both required some additional pre-purchase assessment, just to be sure the horse was going to work in my boarding/training environment. A horse that bites or kicks can sometimes make you unpopular, or can be a liability issue if you are not the only one handling the horse.