Really Cheap Near Mohegan Sun
Depends what you mean by good and inexpensive. Sadly there isn't much in the area outside the casinos.
Illiano's in Norwich has good red sauce Italian -- pizza, pastas, fish and seafood. Reasonable prices. They are out near Dodd Stadium.
In downtown Norwich there is Red House. Very good pan-Asian menu and sushi, though their sushi is not the best in the area. Most entrees are in the ten to twelve dollar range.
Mahzu is closer to Mohegan Sun than either of the above, about five minutes by car. The best sushi in the area and some say the best in Connecticut.
Bella Fiore is right near the casino, Modesto's is a little past Iliano's. More upscale Italian than Iliano's. Neither is cheap, though, by local standards. Fifteen to twenty dollar entrees, with Modesto's a tad higher than Bella Fiore.
Joy's Country Skillet and Olde Tymes have the best breakfast in the area. Olde Tymes' owner is a friend of mine but Joy's has a better breakfast. They close at two. Olde Tyme's serves all three meals but I only like their breakfasts.
In the nearby area there's also a Chili's, Subway and Chen's Buffet (Chinese) and a Stop & Shop all in a complex called Montville Commons, which is about a mile away or less: 2020 Norwich-New London Turnpike Uncasville, CT 06382
We do have several new quick-service dining spots in the casino now as well, which opened this summer, including Pepe's Pizza, The Original Soup Man, and Chief's Bagels, Subs and Sweets.