Sonic's cheeseburger includes a quarter-pound beef patty, sliced tomatoes, chopped onions, shredded lettuce, cheese, crinkle-cut pickles, and a choice of mustard, mayo, and/or ketchup on a toasted bakery-style bun. Their onion rings are breaded and handmade daily.
The burger alone will usually run you over $3 at most Sonic restaurants.
You can find the value-priced special at participating locations for a limited time.
Update 11/6/17 - They've added the option to get a Footlong Quarter Pound Coney instead of the cheeseburger.
Photo via Sonic.