Looking for Cheap Eats near CBD
Prices in New Orleans are quite reasonable. I would suggest that you are well served to not try to eat on the really cheap.
Normally, I would recommend Mr. B's. They aren't open yet but could be by the time you come. I'd check on Bacco's lunch specials. Usually very good and quite reasonable.
And I second the Rio Mar recommendation.
Cheap? Best cheap place would be Country Flame on Iberville and exchange. During lunch there's Commerce Restaurant at Gravier and Camp, po-boy's only I think, since Katrina. Deanie's (not the fried seafood joint from Bucktown, but an ol' time waterfront lunch place) on Annunciation a block or two down from the bridge.
Ugly Dog Saloon cat-a-corner from Deanie's has reasonable barbecue. Then there's Dino's and Warehouse District Pizza.
I'm answering you as if quality and/or the rapport betwween price and quality were not involved. So this is just about cheap.