Well, in Negril...you can spend as much or as little as you choose. You can get a private transfer from the airport for 50-60 US. However, you can go Juta and cut that in half or less. If you drink a bit, bring a cooler or have a room with a small frig. Drinks alone....can save one quite a few bucks if you have them in your room before you head out. Meals, eat where the locals eat. To me, better food at a much better price. The ambiance is fine, but if you are on a budget...you can still eat some great local foods. Buy fresh fruits and veg...and anything local...you will save money.
If you have a coffee maker in your room...you have a good start to breakfast. Buy some bulla, bun/cheese, fresh fruit, yogurt and you have breakfast cheap. Lunch..try some jerk chicken or patties from the locals, or some nice jerk pork from Red Dragon. Dinner...you can splurge or again..go local. Try anywhere that the locals go. You will be assured of getting good food, at a good price. It's up to you. It will always be fun in Negril! Enjoy yourself on whatever budget you choose.