Easyjet aren't using cookies like they did - I remember saving £80 when we lived in Turkey - £80 for around 20 seconds work deleting cookies. Another tip for Easyjet flights is for when you want to book a single rather than a return. Easyjet flights are cheaper as two parts of a return flight, compared with booking one way.
So don't book one way, select both parts of a return. Then when it's all totted up, remove the leg you didn't want. The remaining flight is nearly always cheaper than booking it as a single flight from the off.