Rapa Nui is the most expensive destination in Chile and there is no way around it: one airline flies here, from one city, and the park ticket plus the guide requirement fix your costs before you land.
What a day costs
There is no cheap version of this island. The floor is a residencial room, self-catering from the Atamu Tekena supermarkets and a hired bicycle, with the park ticket on top as one unavoidable block. Note that CONAF's own park page still sends ticket buyers to a website that no longer resolves, so confirm the current price and the place to buy it once you land rather than online.
Only LATAM flies here
Mataveri International (IPC) is the single point of entry and the only direct flights come from Santiago, about five and a half hours. There is no competing carrier and no cheap season worth waiting for, so the flight is booked first and the trip planned around it.
You cannot walk into the main sites alone
Chile's national tourism board states that reaching the principal archaeological sites requires hiring a local guide, on top of the park ticket. Budget a guided day rather than assuming you can improvise your way around the island.
A bicycle beats a car for most of a week
The island is small and the coast roads are the sight; a hired bicycle covers Hanga Roa, Tahai and the near coast with no fuel bill, and the tourism board lists bicycles alongside vehicles as a normal way to get around. Save the vehicle for the day you go out to Rano Raraku and Anakena.
Unbundle: room first, guide second
Family-run rooms in Hanga Roa's back streets sit several tiers below the all-inclusive lodges, which fold guides, meals and park fees into one rate. If you are counting pesos, book the room on its own and buy a guide only for the day you actually need one.