In the port of Piraeus, I found this notice board about taxi fares from the Port to Athens and elsewhere. I publish this, as it can be some use for those who want to travel to and from the port by taxi. I know you cannot read it on this photo, but if you click it, you can see the enlarged version.
And following is the previous fare table. We can see that the tariff is up about 30%.
This 'indicative' fare includes flat rate, toll, and luggage supplement. In each row, the upper price is for daytime and the lower one is for the night (0:00-5:00).
This is correct at the moment of writing,
(Not everyone wants to show the tariff!)