Cheesy deal Before you stuff yourself on Thursday, stuff yourself with savings at Sonic Drive-In. On Nov. 21, the fast-food chain is celebrating Thanksgiving a few days early by offering cheeseburgers at 50 percent off. With no limit, everyone in the clan can chomp on a cheap cheeseburger. To make it a frugal feast, order a large fries and everyone can share, or visit during its daily happy for half-price drinks and slushes from 2 to 4 p.m., too.