No. In general, I don't tip owners, I tip servers or workers who aren't in charge of how much they make. Any taxidermist I've ever used was the owner of his own shop and sets his own prices. I expect him to take pride in his work and set those prices accordingly... Sometimes I've paid extra for certain details I requested, or less because I brought him a lot of work that year... But I always just pay whatever he quotes me at.