Too bad this isn't a contest ... i would have won for sure. I live in belgium btw.
So if my calculation's are correct (metric system here so don't shoot me if they aint cause i suck at math)
1l = 0.264 gallon
1.8€/L = +- 2.31$/L
55l or 14.52 gallon= 127$
1 gallon costs me 8.75$ for 98 octane
(98 here is similar to your 93/94 cause RON=/=MON)