You don't get any discounts by buying them at AAA anyways (maybe for the 4 day hoppers). I just priced it out at my AAA office and they basically read the Disney website to me (effectively they order them from Disney and give them to you - if you're interested in this, any AAA office should be able to order any ticket for you). I guess you save the $3 for shipping. However, I saved $30 or so by buying from
Undercover Tourist (through the mousesavers link). Plus free shipping. The prices seem to vary between there, ticketmania, etc., so check around but I'd really be surprised if AAA was cheaper. Plus, my office at least refused to give me the AAA parking pass even if I bought the tickets through them - I had to book an entire package to get that despite what others have said on the boards.