The classic Greek budget mistake is three islands in ten days. Ferries between island groups frequently route back through Piraeus, so an ambitious plan spends two of ten days on boats and several hundred euros on fares.
Pick one island, by ferry time
| Island | Ferry from Piraeus | Fast fare | Cost level |
|---|---|---|---|
| Hydra | ~1h30 | €30–40 | Moderate |
| Paros | ~3h | €45–60 | Good value |
| Naxos | ~3h30 | €50–65 | Best value |
| Milos | ~3h | €50–65 | Good value |
| Mykonos | ~2h30 | €45–60 | Expensive |
| Santorini | ~5h | €60–80 | Most expensive |
Naxos is the strongest budget choice: large enough to have mountain villages and Venetian towers as well as long sandy beaches, the best food in the Cyclades, and meaningfully cheaper than Santorini or Mykonos.
Milos is the pick if beaches are the priority — Sarakiniko's white volcanic rock looks like nowhere else in Greece.
Santorini delivers exactly the image and is the most crowded and expensive island in the country, with mediocre black-sand beaches and a five-hour ferry that eats a day at each end.
Hydra deserves a mention for short trips: ninety minutes from Athens, no cars at all, and a harbour town of stone mansions.
Athens, which is cheap
Athens is markedly cheaper than the islands and is routinely given one day when it deserves three.
The combined Acropolis ticket covers seven archaeological sites and is good value. The National Archaeological Museum holds the Mycenaean gold and the Antikythera mechanism and is the best museum in the country.
Accommodation runs €40–70 for a decent double, and a taverna meal €10–16. Koukaki and Exarchia are cheaper and better for eating than Plaka.
Free: Filopappou Hill for the Acropolis view, the Sunday Monastiraki flea market, and simply walking Plaka and Anafiotika.
Ferry practicalities
Conventional ferries cost roughly half the high-speed fare and take 60–80 percent longer. On an overnight route that trade is worth making; on a three-hour daytime crossing it usually is not.
Book July and August ahead, particularly for Santorini and Mykonos. May, June, September and October you can buy a day or two out.
The meltemi — a strong northerly in July and August — cancels sailings, sometimes for a day or more. Never plan a ferry back to Athens on the morning of your flight home.
Daily costs
| Item | Shoulder | July–Aug |
|---|---|---|
| Island double room | €45–75 | €90–150 |
| Athens double | €40–70 | €60–95 |
| Taverna meal | €10–16 | €13–20 |
| Gyros | €3–4.50 | €3.50–5 |
| Scooter hire, day | €15–25 | €20–35 |
The gyros at €3–4.50 is the budget traveller's staple and is genuinely good food rather than a compromise.
When to go
Late May to mid-June and September are the best months: sea warm, prices well below peak, islands functioning normally rather than overwhelmed.
August is when Greece itself goes on holiday and it shows in every price and every ferry.
October is still warm and very cheap, with the caveat that some island businesses begin closing for the winter from mid-month.