Prices for flight only to Corfu at ANY time of year are ridiculous! This year we paid £560 for two (in August). Next year for July they are coming up at about £480. Last year in June we paid £440, and similar for September the year before. We booked a last minute package holiday in May to Roda, Corfu (this year) and paid - £400 for the flights, B & B, sea view room, for the both of us for two weeks!
We usually visit Tenerife a few times a year - a destination much further away than Corfu (around 4 1/2 hours) and the flights are usually about £150 each. Work that one out!