Fares have gone up a little this year so i'd expect to pay around 28-30 euros from Lindos to Faliraki. If you want to save a bit of cash you could always get the bus out and taxi back, last bus leaves Lindos at 1915 which is a little early but if you go out for dinner in Faliraki before hitting the bars works out ok.

Have to say Lindos isn't bad for the odd crazy night though, many times i've left Arches Club or Barcode in bright daylight. In fact one night this year i didn't even get to bed, i got back so late that i decided to go straight down the beach and sleep it off in the sun