I live in in Santiago and Easter Island is a once in a lifetime trip, or in our case as I said too many good things to my family about it and we went with them a 2nd time.
If it interests you 100% go, accommodation can be expensive, the food and drinks we didn't find too, too expensive compared to the business district of Santiago/London/our home city of Vancouver.
Car rental is not as expensive as some travel articles may suggest. We rented a "Jimmy" four seater jeep for $40,000clp or about 38GBP a day, be aware car insurance is not really a product they offer so make sure your travel insurance covers you, not that any one is driving fast there. That was last Feb so perhaps prices have changed.
To get from the center of town to the beach it is $5,000CLP (about 5pounds each way, per person) and it is important to note that is per person each way.
The beach is lovely and the empanadas from the beach hut are great. Take some small notes/coins as you can buy fresh sliced fruit.
You can go to the island's only post office and get your passport stamped if that's your thing, my niece and nephew think I'm the coolest Aunt as they have it now in their passports.
There are other spots to visit, extinct volcano, birdman competition area, a museum, granted it's not big, I haven't used this company but this page gives a decent idea of what else Rapa Nui has to offer. imaginaisladepascua.com/en/
The seafood crustacean "rape-rape" pronounced "RAA-PAY, RAA-PAY" is delicious. Check out Tatku Vave for this. If you don't have children with you are in for an...experience...check out Kotaro Bistro. I promise he is not as scary/odd as his blog/website makes him out to be. izakayakotaro.blogspot.com/ but he is still an experience! Reservations are a must as he get the fish in every morning, no fresh fish that he is happy with? No dinner!
When you get off the plane you will pass by a small hut/kiosk this is where you need to buy your CONAF (national parks) tickets, even if you are going on a tour you need to buy these tickets at the airport, it will be BEFORE you enter the terminal to collect your luggage, there is no gangway you just walk down the stairs from the airport onto the tarmac.
Please also note that things have been a little...difficult in Chile in the recent weeks, this is not to suggest your should not come, please do, spend money the tourism sector needs it and the GBP is strong here! Things are reasonably calm here now but could (COULD, I hope not) flare up again so maybe a quick google in the week or so before you come would be a good idea.
If you tell me what area you are staying in I can tell you if that's where the protests usually erupt, as if you are out of the way of protests it's ok. I can also give you recommendations for mainland Chile.
As things may have changed please take this as a guide not the gospel.