Not seen this before

frankiesowner

I'm well aware that 'cheap' flight operators will do their upmost to relieve you of money over and above the 'cost' of a flight but a recent experience with Easyjet was a new one for me. I found a flight, selected it and started the process of booking. So far so good. Many will be experienced with the palaver of booking the flight and the numerous web pages you are taken through to chose seats, chose baggage, resist the insurance, resist the car hire etc etc. Eventually I got to the point of actually paying for the flight. Shock. Upon clicking checkout a message popped up telling me that the cost of the flight has gone up £4 since I stated the process. Paid it...but really takes the biscuit.

bagand96

Airlines well sell a set number of seats at a certain fare bracket, once they are sold the next batch of seats are sold at the next fare bracket and so on.

(That's simplifying it somewhat as flight pricing is dynamic and changes on a number of factors so the fare brackets themselves will also change)

It could be that someone else was booking at the same time and nabbed the seats just before you did. Very rare but it can happen, hence maybe why you haven't seen it before. 

400ixl

Dynamic pricing, has been used by airlines for many many years, budget airlines are more likely to use it throughout the booking process though.