Dear Borismab,
For work I go to Valencia and find the prices there very cheap. I am with locals and have Tapas lunchtimes, but go into the main town and have wonderful food in the restuarants. The bars are cheaper than in Greece, this is remember a huge city so I am very suprised that some parts of Greece have got so expensive.
I have posted on other Greek Sites and still have no answer to this question :-
A bunch of goods from a supermarket in Skiathos is exactly the same price of that in Lesbos. However the price in Restuarants, bars, sunbed prices etc etc is 50-60% more expensive in Skiathos than in Lesbos/Samos. There are many Islands I have'nt visited, but I feel like I've been bushwacked by the Skiathians. In 1996 and 1997 we thought that Skiathos was wonderful value for money. Having talked to many people this year, time and time again it was stated that although the Island is beautiful they will not be coming back due to the expense. If you pick and choose your places to visit in Greece you can still get value for money. But it is getting harder and harder.