My first answer is no way, no how, never!

The reality is, if I were in a position where I could no longer care for my animals properly and being with me meant they would not be cared for in the way they should, and someone who could care for them and who would love them they same as I did, then I would have to think about it. But in that case, I would rather give them to someone for free, that would love them, then someone just because of the money.