Have you considered sharing meals? At some places, the portions are really large.
At AK's Flame Tree BBQ, I remember the 1/2 rack of St Louis Ribs and the 1/2 Chicken platters being HUGE and the members of our group who ordered them (big eaters, by the way) weren't able to finish their meals. If 2 people shared one of these meals (approx $10) and got 2 large fountain drinks (2.50 each) and even got a basket of fries to share ($4), you are at $19 total.
At Pizza Planet in DHS, 2 people could share a pizza and salad ($8.50) 2 drinks (2.50 each) and could each get a cookie ($2 each) for a total of $17.50. Not one of our group of 8 finished our pizza/salad/dessert meals at Pizza Planet; they were way too big for just one person.
You didn't mention DTD, but Wolfgang Puck Express is a great option with large portions. It would be very easy for two people to share one of the pizzas (around $10) and a couple of drinks (about $2 each ) and you've spent a total of $14. A couple of meals at McDonald's doesn't cost much more than that and the quality of the food at WPE is outstanding, IMHO.