Santorini is the most popular Greek destination for romantic holidays, and especially for honeymooners. From hostels to boutique five-star hotels, the island can offer both cheap and very expensive accommodation, depending on what you are looking for. If your target is a hotel or villa on the caldera, keep in mind that not all hotels with sea view have caldera view. Fira, Firostefani, Imerovigli and Oia have such locations, that part of them overlook the east coast which is flat.
The most affordable options can be found around the beaches of Perissa and Perivolos.