I also discovered that the currency in which a fare is quoted can affect the price. A year or two back I was asking the UK call centre whether they could book me an Ex Eur ticket in GBP rather than EUR. They were able to book it at the quoted EUR price with no problem (so it was not a point of sale issue), but translating the fare to GBP cam up with a much higher figure. Very odd and they could not explain the difference.