Went to Zykanthos last summer, last week of july/first week of August, last minute deal from Panorama for €299 pp, we thought that was fantastic until we got there and the accommodation was overbooked so they upgraded us and gave us €75 pp back to compensate.... we were overjoyed. If you can wait until last minute you really get good deals.
But Panorama fly to Zykanthos, and you can book flights from the airport, seat only, for about €150 pp if available, each way.