I agree with pretty much everyone here. I mixed breed dog can be easily found in shelters and rescues, puppies too. I think it would be pretty crazy to pay more than a few hundred dollars for a mixed breed dog, even in CA.
There is a horrible ghetto pet store near my work in a mall and they sell mixed breed puppies most with no papers or ACA or APRI "registration" for $1200 and up! I had a customer buy a morkie from that shop

She brought in her pup and she was 8 weeks old a huge! I thought she was 8 months! She looked nothing like a maltese OR yorkie! Even she herself said the bad thing about mixes is you have no idea how they are going to end up looking, yet she still bought her!