My home field (KOJC) have self service 100LL at US$3.25 per gallon and the Jet-A is US$3.76 (full serve only.) That's only one data point but the price is about average or above average. The 172N (180HP O-360) I fly consumes about 8-9 gallons per hour with judicious leaning. That, unfortunately, is significant cheaper than European prices. I believe landing fees are not as customary here as it is in Europe. Have you consider moving to the US?
Cheers,
Remi