Based on Feb 2011 prices--from mid- beach to Rockhouse should cost anywhere from 10 to 15 US$. You can take a route taxi to town for
200J per person. It was 100J pp to roundabout, then you pay another route taxi 100J to go to town or further into west end cliffs. You don't have to change taxis if you make a deal with first route taxi for 200J pp. I don't know if the price has gone up , because airport
transfers have gone up since then.