I often receive requests for cost of living information from people considering life in Greece. My short answer is that Greece is not cheaper than anywhere else but that we live more simply on our island.
Below is what I wrote to a single, retired man who already lives simply in another country:
Off the top of my head I would say the following is a minimum budget for subsistence: In Euro per month
Rent on one bedroom flat within walking distance of shops and restaurants: 200
Electricity w/o heat or air conditioning 30
Telephone/ADSL internet package 50
Groceries 200
If you choose your flat wisely you will not need air conditioning because of breezes. Heating by electricity could run more than 300 Euro per winter; by oil easily 100 Euro less; wood about the same as oil. You can get better but not cheaper accommodation if you invest in transportation.
Of course most people will want and can afford better than that. Many wealthy people live well on Paros as well.
Yesterday I discovered another blogger who took a more extensive approach to comparing the cost of living between New York City and Athens. I would guess the results would surprise New Yorkers but not Athenians.
The article is too long and involved to summarize. I will just quote two items from her chart: in Euro
Athens New York
Haagen Dazs (500 ml) 6.32 3.07
Rice (500 gm) .55 .67
See the entire article and chart here:
http://livingingreece.gr/2008/11/10/greece-usa-price-comparison/
I always welcome emails about expat life; please write with your specific questions.