Marketplace
EASTERTREAT40NZ
Virgin Australia is offering return flights to Tonga for $302 via BYOJet using the code EASTERTREAT40NZ. Haven't seen fares to Tonga this cheap since 2015. Fares include bags, seats, and meals.
BTW, you can use the code for any return international flight which is a good deal on its own.
Flight tip via Scott's Cheap Flights