I can confirm that Beer in Sidari varies between €1-2, usually at certain times and for draft beer.
Above prices as well, most specials vary between €6-8.
All the Supermarkets in San Stefanos are really expensive with jacked - up prices as they only usually open in the season mainly!!
Go to the Big Supermarket on the Crossroads as you head out of Sidari towards Corfu Town & shop for the week.
For example a tin of Baked Beans there is €1.20, while in S S we paid €2.60 - (yes baked beans!! - had to get them for the grandson!).
Try to take with you all your suncreams & basics for the bathroom etc. Sugar, coffee, tea, butter, all expensive!
Take salt & Pepper and a small cooking oil, ketchup it all adds up to a big bill!!
I overspent last years budget - this year by around £3-400.
I negotiated a last minute - 2 days car hire (opp. the condor), for €60, 5 seater Fiat Panda, inc child seat.