I know that line of thought.... I have it often.
My current main ride is a Honda VTX 1800.... Love it but frankly at 40 mpg and a tiny tank?
I regularly travel to the west coast of Scotland from home in Tunbridge Wells.
I can do that run so very much cheaper in my old Skoda Superb diesel than I can on any bike I've ever ridden.
But, hey, if it were all about practical we wouldn't be riding bikes at all.
On the other hand I did baulk at the running costs of a Rocket 3.....I do 18k every year......and I too did the maths.
Al

I took the Road Less Travelled. Now where the ****** am I?