The government here collect about 70% of each liter in taxes.
The price is similar throughout the other Scandinavian countries. Even in Norway, which is the only one of the Scandic ones that process oil on a big scale, the price is similar as ours.
The reason being, at least here, is probably:
Small market
Long distances for each shipment
Last month they even had to shut down all of GA ( at least the ones that used piston engines ) because the vapour pressure (?) of the gas was to low.
But that was probably because of damaged shipment last year ( yes the 100LL is shipped about once a year )
But this is how it has always been, and probably will be. ( we are only 288K souls )
Regard
Proxus