Once you get to Fiji it's likely you want to get going as soon as possible. I wanted to do the same, but I wish I knew a bit more before I jumped in.
Prices vary according to how you book and who you book with...
- Hostelworld/Hostelbookers will save you money and can halve the price of a hostel compared to walk ins. Great example of this is Smugglers Cove where the markup is astronomical.
- Inhouse travel agents at the hostels are well versed and convinient but can cost you more and may talk only of the main touristy options. Ask them about other areas - Bamboo Beach Hostel was helpful at giving alternative options to the Yasawas.
- Phoning or emailing resorts directly can save you money as they get all the money rather than paying agents etc.
- Resort websites may offer deals. For example when I looked Beachcomber offered 4 nights at a discounted price plus free transfers from the mainland.
You will be given handwritten confirmation only, so keep on to that paper and only surrender it on the last journey or when you reach the island. Keep it in your sight and make sure all details are on there.
Sometimes you can change your mind. For example my boat from Mana to Beachcomber could be changed so I could go from Mana straight to the mainland. My deposit from one resort was transferred to another. My specified boat journeys were changed to fit my new plans - the only money I lost was $10 as the new itinerary was this much cheaper. Some places will charge a percentage or the full amount (Beachcomber) but if you speak with them nicely you may not have to pay.
Preparations for the IslandsTo Buy...
Water, as it will be expensive. You shouldn't have a problem taking a six-pack on the boat, but try keep the bottles in a sturdy bag or something similar for easy transfer.