Taveuni Ocean Sports is superb, for a budget friendly stay, you can book a dorm room at Maravu pay backpacker prices and still have the amenities of a resort. There is a great pizza joint walking distance from Maravu that has seafood and an ocean view. A cheap eat from a market or store is called ROTI, which is like a stuffed tortilla with varied fillings (tuna, vegetarian, or my favorite curry) and costs 1-2 FJD.
Taveuni is on my annual bucket list and is well worth the additional flight cost from Nadi. Review luggage weight restrictions for domestic travel if booked separately. If you have any spare room in your suitcase, please bring reward stickers and colored pencils for the Naselesele school near Matei, or any other remote school you may be near. Enjoy!