Good to know. I've been using Dorian's chart as the basis for my questions. As of today, the conversion to dollars still puts the UK as the best price for economy, but that could, of course, change based on the currency markets.

In our case, I don't think we could go the no-advance-purchase route and just book the ticket directly upon arrival in the country--SAS in Sweden for example. We actually want to plan several tours and sightseeing visits on our trip RTW, and would need to know our flights in advance to plan the on-the-ground stuff. In such a case, is the travel agent route still the best? Also, still not sure about the payment questions...