Q. For a couple of weeks we've been eyeing a one-way fare on Adria Airways from Tirana to Ljubljana, on Saturday, August 16 for €120. The Sunday fare is €185 and there is only one flight per day. We were in the middle of booking the Saturday flight (which at that time appeared to be empty since and we had our choice of seats) but there was a delay having to with our credit card, then access to the site expired. When I started all over again and the fare had changed suddenly to €157. We then tried again, erasing all our cookies, but this didn't work. What's going on?

A. This could simply be because the airline changed the airfare, or the number of seats at the lowest fare has changed. Airfares change all the time on any given route, and there’s no magic to finding the cheapest seats other than searching constantly and signing up for airfare alerts and pouncing immediately when a fare looks cheap. And while there’s no solid evidence that clearing cookies changes the game, it never hurts to try.