You may not have known this but I have been to Greece more than 20 times and can even speak a little Greek. Flights to Greece are typically very expensive – over $1,000.
Right now, via Finnair (in conjunction with other One World carriers) there are incredibly cheap flights to the romantic island of Santorini!
Most of these flights are in May and have stops in Helsinki, often with enough time to check out the city.
May is a perfect time to visit Santorini. It is Spring and just getting warm. It is usually still considered low season, so hotel prices are affordable.