I think they are very cute but I would not pay $10 over regular polos for them. A pair of 2 patterned polos sells here for $12 - $14 (depending on the tackstore) made by a specific company (homemade like yours would be as well I do believe). I think you could fetch that price but I wouldn't try anymore... lots of people have turned to boots these days as well. An idea would be to bejewel fly bonnets along the edges. I would be interested in something like that for sure! Good luck!
Did you make the polo yourself as well? My biggest concern is that they would fall off in the wash, or extended wear. Are they sewn on? They look good in black, but Im not sure about other colors. I don't use black polos on my mare because she's white, so you see every single hair stuck to them.