Depends where you go to eat as the JB have lots of restaurants with differing prices and atomospheres.
Eg. Bacardi and Coke in JB English pub was about £5 and a bottle of guinness about the same, whereas in the Burj it was approx £8.
We ate in the Argentian restaurant on the 25 floor (which was okay, nothing special) and the meals came to about £40 with wine on top.
We also ate in their Italian restaurant (which was very nice) but didn't have a 3 course as pasta tends to be really filling and paid about the same sort of price. Wine tends to be expensive and you're looking at approx £25=35 for a half decent bottle.
We didn't bother with lunch though as the Burj's breakfasts were really filling and just tended to stop off and grab a Starbucks or something similar if we went shopping in the main malls. From the Carrefour in Deira City centre you can pick up bottles/cans of pop and bottles of water if you want to stock up during the day. However, bottles of water/fruit etc were provided by our hotel if you were sunbathing.
You must dine around the Madinat Jum hotels as I think their choice of restaurants is brilliant also, just hop on the golf buggy and away you go!
Hope that helps a little.
