Well if you get lobster from the beach guy he will try to get you for $9 per pound.. It's already cooked but just doesn't appeal to me knowing he's been walking the beach with it just in a box.. And the restaurants are more like almost $20 for a lobster dinner.. So no.. Not true.. But that being said I do get it at least 2 times when I am there.. lol. Local fish will be cheaper, and very fresh. Think red snapper and king fish.
Breakfast can be anywhere from a few dollars to 10pp.. I love Alfred's for breakfast, Selina's is great too. Yummy.. Ackee and salt fish being the cheaper choice typically, beside just getting toast. lol. Lunch can again be anywhere from a few dollars for a Jamaican patty with coco bread, yummy, or up to $10-12 for other things.. We always split jerk chicken from best in the West, love it.. Cosmos is great for lunch, they have some decent fish specials. Dinners can be anywhere from 7-22pp.. Fish is usually around $400J= around $5.50 USD..
Small places, where you see locals going and taxi's stopping at, are the places to be..
Traditional dishes usually run cheaper. Curry goat, ox tail, ackee and saltfish, brown stew chicken, patties and coco bread, etc.. Making my mouth water thinking of them.. For the 2 of you I would budget about $100 per day.. Thats for food, drinks and whatever.. You should be more than fine, and $$ not spent can just be used for excursions or to save for the next trip.
Take ALOT of small bills with you and change some $$ when there, or just go up to the round about ATM.. Most machines dispense in J's, there is one that does USD though. Or change $$ at the Cambio, many hotels change $$ for a fee as well..
Take along a cheat sheet too. It's very helpful so you don't have to do as much math..
http://www.oanda.com/convert/cheatsheet
Check out
http://www.negrilinfo.com for a map of Negril and a few suggestions on where to eat and drink..