I don't think $600 is too much especially if she is up to date on her shots (around here that would be about $200-$250). She is adorable, a good size for a child and housebroken -- that is a huge plus to me. If I had bought Gus for someone, I think they would have wanted to smack me for the gift I gave them. He was so hard to housebreak.
If the breeder said she is good with children, I would get her.