Jo
i asked Olga's Travel this question the other day and was told it's 2%. They all do a good exchage rate though. I remember that, when in the Alpha Bank at Acharavi, last September I noticed they only charged 1.5% so, out of interest, changed up some sterling. Back in Arillas I changed the same amount of sterling and even with their 2% got more euros than the Bank. - Strange that.
If you can get commission free sterling travellers cheques in England then bring those.
You will get more for your money. ( It was about 1.467 exchange in Arillas yesterday )
Negg