The Spca is also a good choice I went to the one on Berkeley on 9th st. There are several rescue centers that are good too. Including one for older pets which is highly recomended.
There are not actual dogs at petsmart to buy. PetSmart sells pet supplies and smaller pets like mice, fish, baby reptiles, and birds. Sometimes they have cats to adopt. They sometimes have dog adoption events and bring in the dogs. But I haven't seen that happening lately. You will need to look around online and Google shelters. I recommend going to a shelter to adopt a dog. The price does vary a lot depending on the kind of dog you want. I adopted mine from the Animal Humane Society.
Thanks! Your answer is awaiting moderation.