Pulled up the menu for maybe our best not-super-formal but still very nice restaurants in Columbia, SC. Appetizers are $12-19, main courses $25-$46, soup and salad $6-$12, and dessert $9.
I think dinner with salad and soft drink at our casual neighborhood Greek/Italian place has probably been averaging around $20 a person.
Habitual bagel place is about $13.50 for a sausage, egg, and cheese on bagel; fruit salad; and soft-drink or tea.
McDonald's wanted something over $6 for a cheeseburger and soft-drink yesterday on the way home from work. After they took a while to realize I was there, misheard my tea order and didn't stick on long enough for me to correct it to unsweet, and then took several minutes with the car in front of me at the register (at one point I told myself they had 3 minutes when I noticed they were slow - apparently they don't keep change at the window?) so I just drove off. If they aren't fast or cheap I'm not sure what purpose they serve.