Everything is more expensive in Hawaii, it's just a fact of life. There is a local dairy on Oahu, Meadow Gold, so they may be a little cheaper than the stuff shipped in from the mainland. As for seafood, stick to the local stuff (Ahi, Mahi Mahi, snapper) check out www.hawaiiseafood.com to find others. Fresh coconuts are in abundance, but I'm not sure about coconut oil. There are coconut trees everywhere, and very few people actually eat the coconut in their own backyard! As you meet people, ask them if you can have their coconuts. If you can, hit the farmers market, where you should be able to get local, less expensive veggies. You'll notice a lot of the "local" food is heavy with salt and sugar, and a lot of meat in restaurants are covered in a sweet sauce. Probably best to stick to cooking your own. Best of luck and congrats on becoming a grad student! Aloha!