This year most people appear to be hiring cars from the airport. However, for those that require a taxi transfer, I think it would be useful to list the typical costs when using a local taxi firm.
The variations in price I have seen quoted on the internet are enormous. It is also worth stressing that in Greece you pay for the journey, not per person, and therefore if a number of people are sharing the taxi it can be quite economical.
From lourdataholidays.co.uk/airporttransfer.php I have found these charges which I think are typical (plus or minus €5.00).
Agia Efimia €60.00
I would expect most of the other local taxi firms to be very similar. I quote this one as I have used Makis for many years and found him reliable.
I hope someone will add to this for the shorter journeys from the airport such as Lassi and Argostoli. Then new visitors will have a good idea as to what they should be paying.