"a documented flawed/compromised design with a discontinued engine and poor dealer and factory support (in the U.S. at least)"
History says that it takes some time for an out of production vehicle to achieve some sort of "classic" status and hence break out of normal depreciation.
You buy a new car ... run it and enjoy it ... and on selling it expect to get less back than you paid for it. Morgans depreciate less than many but if you have £50k/$50k/€50k in your pocket, there are loads of different ways of spending it other than buying an M3W so don't expect financial miracles. Ours is a keeper to enjoy and its long term fate is our son's problem!