I've no idea how much the taxes were on this particular flight but if they were £20 for each person (and maybe for each sector) he may have been travelling with his wife and kids, and if that were so it sounds like RYR are applying an administration charge to each passenger (and maybe each sector) rather than just to each booking. Am not sure if the other airlines do that but if they do it sounds like sharp practice....
Carr30, You should be able to give us RYR's policy on this, I seem to remember that you work for RYR