Pension Livadaros is a great choice for a budget stay in Santorini. The rooms are very clean, the hosts (family-run) are very friendly and the pool is a dream in the hot temperatures - it looks as pictured and I didn't want to get out of it. The location (Karterados) is also convenient - it is very close (one bus stop) to the main town of Fira and it's an easy to return to the airport, plus small grocery and restaurants nearby if you want to grab something local after a long day. The Pension provides airport pickup which is a bonus, and for a fee, you can also get an airport return at an early morning hour before the buses start if needed. Don't forget to bring toiletries as they are not provided.