When i was enquiring about days trips with San Stefanos Travel, i discovered their taxi service. It is €55 each way.
If you do a google search for San Stefanos travel, they have an online form you can fill in if you want to book with them, or you could do it via email (their email address is on their website)
They were very efficient with their replies.
It did say on their website though that you need to book a week (at least) before, to give them chance to process the booking.
Of course there'll be plenty of other options, that's just the one i came across
Rachel x