Lelystad had the most expensive avgas I have ever had - this side of LTBH in Turkey
Avoiding mandatory handling by taxiing to a maintenance facility or an aeroclub is standard procedure, but you need to arrange it with the said organisation beforehand.
You also need to make sure they do pay the airport on your behalf. There is a certain "business" at Norwich which last time I went there evidently had difficulties in passing over my money to the airport, and the airport eventually chased me for the (much larger) landing fee. Same happens at Bournemouth... but there I was told by the handling agent that I must go via him even if I am visiting somebody.