There may be some advantages with going through breeder but I found a few issues when I was searching for my CAG. When I was doing my searches for an African Grey (both three weeks ago as well as six months ago), I found several potential breeders but none were local and the shipping would only be about $100 to $200 difference. The other problem is that I would not be able to observe the bird's demeanor before taking it home. Not to mention all the scams I found online.
That was the reason I decided to stick with pet stores in Los Angeles, California and Phoenix, Arizona. And, after visiting and talking to different store, you get a feel for the quality of the store and how they care for the bird.
For example, the first question I was (sternly asked) when I when to Parrots Naturally was, "have you been in any other bird stores today?" and then immediately "have you held any other birds today?" Only after I said "no", I was told to use the hand sanitizer and they would bring out the bird they MAY sell to me. I was not allowed to go to the "bird area." They also told me they would probably not sell me the bird that day "because it's traumatic for the bird" and I would have to come back several times to bond with the bird as well as go through an interview process to ensure I had the proper cage, diet, and commitment levels.
In contrast, I got my CAG from a pet store were he was in a 3 foot by 2 foot cage with no perches. I decided to go with this CAG because I felt sorry for him and after visiting the store 3-4 different times, I like his personality. Also, I'm sure the CAG at the other store would be going to a good home because the owner would see to that (during the interviews). The hardest part for me was trying to use what I learned researching for signs of illness (nasal discharge, feather condition, pinning, dropping color, etc.) to tell if the CAG was relatively healthy.
So, with all the pet stores I've visited, I would consider only two ("Parrots Naturally" and the "Perfect Parrot") where selling very well care for birds. One shop was actually selling unweaned CAGs to me, a person with no prior weaning experience! This is illegal in California by the way - not to mention the risks of burned crop or aspiration.
One last thing with pet store, they have a high profit margin so when you tell them you’re planning on going with another bird at another store, they may be more flexible on the price. I did this to the store where my CAG was and told them that I was considering a younger and better cared for bird at a much lower price than they one they had in the store. I think the original price they wanted was $1,300 but they dropped it down to $950.