They don't need to worry at all .
Firstly there's always plenty of taxis waiting just outside arrivals, they're metered and cheaper than here in the UK. Also Ixia is only a short 10-15 minute ride from the airport. I'd estimate around 10 euros.

I found this on the Grrek Island site:-


Rhodes taxi fares



Taxi prices from Rhodes airport (one way)
Ialysos €10; Rhodes City €14; Faliraki €15; Afandou €16 (from Rhodes City); Tsambika €26; Kamiros €27; Lardos €34 (from Rhodes City); Lindos €35; Pefkos €37; Empona €37; Kiotari €39; Monolithos €45; Gennadi €45; Prasonisi €70.
Extras may include luggage, night rate etc.

I've no idea when the site was updated, so don't blame me if the prices have gone up again!!



Parky

Last year we paid 12 euros to Ixia.

Cathy

Just make sure that they get a rough estimate before they get in! BUt I've never had a problem.

Where the taxi's line up at the airport will be a board showing the prices to most of the popular destinations on the island. Taxi fairs are fixed by the island administrators to stop tourists being ripped off. But like the earlier post said just double check the price if you are on a night flight. Used them a few times from airport to Lindos and back we have never been charged extra for luggage yet. Last year 35 Euro.