From Kathimerini, May 2009:
Taxi fare charges are now up 33 percent to 48 cents from 36 cents per kilometer. The next increase will be in November, when the rate will rise to 60 cents, and the final hike is due in May 2010, when it will reach 72 cents. The minimum charge for a cab ride, 3.80 euros, will not change. In exchange for the fare increase, cabbies have vowed to stop common violations such as overcharging and taking on multiple fares.
So from this taxi fares should be:
Sep 2008 42
Sep 2009 56
Now 71
Sep 2010 85
This is Tarrif 1 remember, there is a Tarrif 2 for Midnight - 6am.
Not sure how set fares are affected by this. All a bit confusing.
Easiest thing to do is just e-mail Zach nearer the time and ask him.