Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Indonesia to Tonga as you normally would.
Denpasar Bali Ngurah Rai Airport is DPS and Nuku‘alofa Fua'Amotu Intl Airport is TBU. These codes are created by the International Air Transport Association (IATA) and airlines use them to identify the departing and arrival airports in the flight routes they service. This flight route has multiple associated airports, so we think it might be helpful to learn the name and codes of them as well. They are Jakarta Soekarno-Hatta Intl Airport (CGK), Surabaya Juanda Airport (SUB), Praya Lombok Intl Airport (LOP), Medan Kuala Namu Intl Airport (KNO), Yogyakarta Intl Airport (YIA).