Is this all going to have a knock-on affect on the price of Efes ?
Yes, it is. Current price of Efes at a bar/cafe is about 7.5tl. Using the above calculations (7.5 x 10%) + (100% x 7.5) = 15.75tl.
Then, take away the number you first thought of and then, "hey presto"- your new price!
But this will only apply to ex pats. Locals or ex-pats with kimlik will not have to pay, or at least get a discount amounting to 112%
Simples...