Perhaps you’ve never had mac & cheese when prepared well. Have a browned crust on top thick with cheddar cheese and large chunks of cheese mixed with cream and real butter throughout the dish, instead of some powdered cheese mix. Don’t overcook the pasta. This type of preparation gets a premium price. You can also do combos such as "Macaroni with Four Cheeses" for a more upscale image and price.
Having this type of dish on the menu offers a choice for many vegetarian customers who eat dairy products, as well as a familiar and well-loved choice for those of us who grew up with Southern-style food.