For a start some info Leah shared with us earlier:
With regards to a transfer from Athens airport, the price varies from 280-380 euro depending on the time of day,luggage and number of passengers. The price can be agreed in advance if you would like to send me some more information over email I would be happy to check the exact price for you.
Kind regards,
Leah Lenihan
on behalf of Starwood Costa Navarino