Not sure about retail sources, but I'd vote for Restaurant Depot, otherwise. I go to the one in Norcross, and they tend to have bone-in rib roasts in Select grade (Wal Mart quality), Choice grade (their Angus brand), and sometimes Prime grade. They also carry Halal beef, but I'm not sure if there are bone-in rib roasts. They also have deboned roasts (aka whole ribeye). Generally, the prices aren't outrageous, so it's worth it if you can find a way to get in. FYI, the one off Chattahoochee on the west side carries slightly different stuff.