Transport between them can be patchy, but a new service linking Zakynthos with Corfu which started this year now brings all the islands (bar Kythira) together. Zakynthos is otherwise linked to Kefallonia with an old-style open deck ‘slipper’ ferry; Kefallonia includes Ithaki on its local small ferry route to Nydri on Lefkada. There is no link (except for the new service) from Lefkada to Paxi/Corfu. Corfu has links to Paxi and its little know satellite islands just to the north. Kythira has an airport with flights to Athens and ferries to Crete (Kissamos) and the Peloponnese (Gythio, Kalamata, and Neapoli).
Comfortable accommodation in May for 2 persons can be found for between €40 and €80 per night. A meal for two that includes a starter, two main meals, salad and a litre carafe of local wine will cost you around €25-35. This can vary widely depending of level of establishment you eat at. A cheap vegetarian dish (pulses or vegetable) will set you back by no more than €5-6 a plate. If you get your breakfast included at the hotel, that is good because breakfast can add another €15 for the two of you per day.
The island’s next hotspot may be The Shore Club, the only development on Providenciales’ Long Bay Beach with 106 ocean view suites and six luxury villas on a nine-acre stretch. On popular, pristine Grace Bay Beach, Grace Bay Club’s tropical-chic redesign led by interior designer Thom Filicia includes redesigned lobby and guest rooms, the new Infiniti Restaurant and Raw Bar and The Residences, a trio of freestanding, beachfront villas. To get off the radar, the eco-conscious Sailrock Resort debuts this year on untouched South Caicos Island — secluded beaches are the buzz.
Those are 3 great islands. Corfu is much more green than Crete and Santorini and does have a different feel (more Italian but it’s no where near Turkey). The trouble with doing all 3 is that Corfu is on the opposite side of Greece from Crete and Santorini so you’d need to fly via Athens. It’s better for most people to visit another Cycladic island (Naxos, Paros, Milos, Folegandros) instead of splitting up their trip between the two sides of the country.
You seem to have your heart set on Zakynthos but I have to say it’s not a good use of time for a sort-of overrated payoff. Your time is much better spent (in my opinion) seeing another Greek island in the cyclades (maybe taking a ferry to Naxos or Paros sitting outside on the deck drinking a bottle of wine) rather than taking a bus and connecting flights. Zakynthos and Santorini/Mykonos are on opposite sides of the country and the only way from one to the other is by flying (or some combination of bus and ferry). So, my recommendation is to consider spending those Zakynthos days in Naxos, Paros, Milos, or some other Cycladic island.
My sister (32 years young) and myself (28 years young) are traveling to Greece from 22nd Aug – 6th Sept 2017. This will be the first visit for my sister and my second visit so I am trying to show her my favourite places as well as visit new ones myself (i have only ever been to mykonos and santorini). Our trip starts in Athens for 2 days, Mykonos for 6 days, Santorini for 5 days and leaving us with 3 days to spare at the end of the trip. (4th Sept – 7th Sept) We fly out of Athens in the am on the 7th Sept so need to be back in Athens prior to this.