AAA will only do the member, but will do family members for 7.95, so it still is a pretty good deal.
The warning about the baby pics is right on. For our 8 month old, we first went to JC Penney because it was convenient, but when we went to the passport agency, the agent told us that the picture was not regulation size (it was like 1.75" wide) and the head was not big enough. She was willing to send it in, but said they would likely call us and tell us to send new pics. So she kindly finished the paperwork and held the application while we ran to AAA and got new pics.
So just a warning, make sure the pics are 2"x2" and the head is at least an inch, or you may get rejected. The passport agent told us, just because the pics come in a nice little cardboard folder doesn't mean the photographer knows what they are doing!
At AAA I knelt on the floor and held the baby on my head against the wall, and the pics came out great.