I like it, but I wouldn't buy it. My brushes get torn up, and I'm cheap, so I wouldn't spend any extra on a pretty brush. I really like the idea of adding the horse's name to the brush, though. Or maybe even the barn name or the owner's name. They're cute, I'm sure you'll find people to buy them, especially if you let them pick the colors and do whole sets.
You should also put a coat of clear nail polish on the brush to keep the paint from chipping.