Rather than combing through the local shops for affordable sunscreen, it makes far more financial sense to pack the tube you have at home. The same applies to almost anything else that you can bring from home including medicine for common ailments. Ideally, if you are on a budget, the local shops should be reserved for emergency purchases only. If you do not have your own set of beach gear, you can always ask your friends to lend them to you for your trip. Just remember to buy them a nice souvenir before you leave!