How old is your child?? I just typed in the info on Disney's web site for 2 adults, 1 child aged 12 (I wasn't sure of the age so I added in an "older" child; a younger child 9 or under would cost a bit less because their portion of the dining package would be less), 3 night at Pop Century in a standard room, with 3-day park hoppers (you mentioned you'd only be in the parks for 2 1/2 days), comes out to:
Disney's Pop Century Resort Package Total:
$1,441.33
02/28/06 for 3 nights
2 Adults, 1 Child
Feel groovy on a nostalgic stroll through decades past in this rad Resort hotel that takes a colorful cruise from the 1950s through the 1990s.
Resort Category: Value
Room Type:
Standard View Room
Ticket Type:
3-Day Magic Your Way with Park Hopper option
Package Type:
Magic Your Way Package with Dining
Includes Disney's Magical Express!
I would think that the
AAA travel agent would be saving you more than $22. Do you know if her package includes 4 days park hoppers? When I entered your info, the computer automatically defaulted to 4 day park hoppers, I had to manually change it to 3 day park hoppers. Ask the agent, this change could save you even more money.
CRO stands for Central Reservations Office, and it's the place you call when you call Disney directly to book a Disney resort room or package. But you can't call them and get the AAA discount AND a package together, that must be done through a AAA travel agent. We have AAA, and I wish they'd let us book this package directly with CRO (Disney) because I have no confidence in turning my booking over to a AAA agent.
TO answer some of your other concerns: No, I don't think you're better off waiting until you get there and buying park tickets each day; it's cheaper to get the tickets in advance, for however many days you'll be doing parks for. I also think the Dining Plan is a great idea for most families.
**********************************************************
Edited to add: I just re-entered the info, but this time using a child under the age of 9, and this is the price quote I was given:
Disney's Pop Century Resort Package Total:
$1,326.25
02/28/06 for 3 nights
2 Adults, 1 Child
Feel groovy on a nostalgic stroll through decades past in this rad Resort hotel that takes a colorful cruise from the 1950s through the 1990s.
Resort Category: Value
Room Type: Standard View Room
Ticket Type: 3-Day Magic Your Way with Park Hopper option
Package Type: Magic Your Way Package with Dining
Includes Disney's Magical Express!
NEITHER of the above quotes take into account any kind of AAA discount, so your AAA travel agent should be able to give you a better price than these!!! 
