The Soda Shop - What can you say... it is a Davidson institution. As the first reviewer mentioned, one thing you absolutely want to keep in mind is that the restaurant is cash only. And, you should bring plenty of cash because the restaurant is deceptively expensive. Lunch at the Soda Shop is going to cost you more than the same meal would cost in many large cities. You are paying for the atmosphere.
The food is generally quite good. There is nothing fancy here - burgers, sandwiches (including things like egg salad), and wraps. They also have shakes and ice cream desserts. (They serve breakfast, though the restaurant doesn't open very early.) The price of most of the sandwiches is in the range from four to six dollars. That includes a bag of chips or a small cup of the side of the day (typically something like potato salad) plus a pickle spear. For an extra dollar you can order cottage fries or sweet potato fries, and they are both very good.
When I go to the Soda Shop I typically get a sandwich, cottage fries, and a soda. With tax and tip I spend $10. It is a place that I go infrequently - not because I don't like it, but because I think that's too much for what you are getting. Nonetheless, the place is busy almost all the time and you are probably going to have to wait if you show up during the prime lunch hour. The first reviewer's tip about sitting at the counter is really a good one.