That's because the Merc is designed to dispatch 1000km as easily as 100km.
The Morgan dates back to the days when own lunatics drove 1000km at a time (usually delivering care overnight to Geneva). The 2 can't be compared - after all what is the future value of Plus4 vs the Merc (ignoring liquidity!).
You buy a Morgan with your heart.
I disagree, the two can be compared if the comparison is about how do you spend your spare cash and which toy do you go for. Not all of us can afford a fleet of cars, I for one can only afford one such toy and therefore it has to give a return, its true that return can be emotional as in the case of the Mog (mostly) but I believe MMC takes advantage of the (blind) faith held by many of us especially when it comes to basic equipment/comfort and reliability issues.