Here's some info on what food prices are like outside Aulani:
Sit-down breakfast at a casual restaurant such as Anna Miller's - $12-$15pp including coffee, tip, and tax
Light lunch/snack - $7-$10pp
Casual sit-down restaurant dinner at a local spot like Zippy's or Big City Diner: $15-$20pp including soda, tip, and tax
Restaurant dinner someplace similar to CPK, Chili's, Applebees: $30-$40pp including a soda, tip, and tax
Most of the nicer restaurants on Oahu are located in hotels, so prices will be similar to AmaAma. I think nice restaurants that are NOT located in hotels (i.e. Alan Wong's) are just as expensive.
The food in the shopping complex across from Aulani, while cheaper than Aulani, is still a tiny bit more expensive than comparable meals in Kapolei, a 5 minute drive away.
For what it's worth, my family of 2 adults and 1 toddler who eats like a 9yo consistently spent $40-$45 per counter service meal at Aulani. Snacks REALLY ate into our budget, about $40/day . . . because we just HAD to have the Mickey bars, shave, ice, donuts, cookies, and sodas