Hi
No, you cant pay the AAA rate and get the pay for 4 play for free as well. Unfortunately you have to choose one or the other.
The difference is about $50.00 per night so you really have to calculate how much you'll actually be saving with the 2 adult tickets.
I would personally take the AAA rate if it's still available. You figure for 4 nts at 191+tax (thats the AAA rate that I got for 07/07) vs 239+tax, thats a difference of $200.00 right there. The Universal Studios website is currently selling a 2 park, unlimited admission for 7 consecutive day pass to usf and ioa for $85.00.
You would definately save by taking the AAA rate and purchasing your tickets seperately, IMHO.
Hope this helps.