That is the useful thing to know, because it means this trip is a location decision before it is a hotel decision. If you want what a Greek luxury holiday actually is, you are choosing between about three places.
For what any of it costs, what a Greece trip costs has the honest ranges including the top of the market. This page is about where, not how much.
The Santorini caldera
The caldera rim is the most expensive real estate in the Greek islands, and it is expensive for a reason that is not marketing: the view is genuinely unrepeatable, and only a narrow strip of the island has it.
The trade is that Santorini is the priciest island in Greece and the most day-tripped, and that the luxury here is a view product. If the caldera is not what you want, paying caldera prices is the most common expensive mistake in Greece. Santorini vs Naxos puts that plainly - only Santorini has the caldera, and nothing on Naxos replaces it.
Where to stay in Santorini covers which villages have the view and which have the quiet.
Mykonos, and its south coast
Mykonos is the other famous one, and its luxury is a scene product rather than a view product. Psarou is the glamour end of the south coast, and the island’s beach clubs run day-to-night in a way nothing else in Greece does.
That is a specific taste, and the honest test is whether you want to be at the scene. Where to stay in Mykonos is built around the choice between the town, a south-coast beach and deliberately away from both.
Elounda, on Crete
The one people outside Greece know least and the one that changes the trip most. Elounda, out east in Lasithi near Agios Nikolaos, is Crete’s luxury strip - quieter and more spread out, with resorts, the boat to Spinalonga and a slower pace.
It suits repeat visitors and road-trippers more than a first short trip, and it comes with an advantage the Cyclades cannot match: outside the Elounda luxury strip, Crete is generally better value than Santorini or Mykonos for both hotels and food. You can pair an expensive week with a cheap one on the same island.
The Crete itinerary splits the island by region, and Elounda sits in the east.
What luxury Greece does not mean
Two things worth saying, because they cost people money.
It does not mean the best island. Naxos, Paros, Kefalonia and the Dodecanese are simply not where that tier is concentrated, which says nothing about how good they are to be on. If your priority is the island rather than the room, the comparisons will serve you better than this page.
It does not buy you out of the geography. A caldera suite still leaves you on an island where taxis are famously few, and an Elounda resort is still an hour of winding road from most of Crete. The transfer pages are worth reading even at the top of the market.
Pairing it
The strongest luxury shape in Greece is two centres, not four: one of the three strips above, plus somewhere that is good rather than expensive. The itineraries sequence the legs, and honeymoons covers the version of this trip most people are actually planning.