Susan, Have you ever sold a snake that you no longer "needed" (perhaps you no longer "needed" the hets, it was a poor breeder, or the fascination ran out)? How is buying a dog for a specific purpose and it not fulfilling that purpose (or being replaced by a "visual morph") then selling it any different?
Sorry I dont seen anything different than what many of us do on a daily basis.
And yes, I have a dog, and I love him, and I got him for a specific purpose (to be a companion) if he stops being that and stops doing his job I will get rid of him.
As a note: I did not say his purpose was a working dog, he is one (versatile gun dog, points, retrieves, and tracks wounded/dead animals), and does a great job at it, but his main role, the reason I got him was a companion. If I had got him just to work and hunt, and he stopped doing that or never did, he would be gone in an instant, same as if I got him as a stud and he couldnt do that.