Billy wrote:
/snip/
I know shutters are not such an extreme example (we are also getting
white to match the trim - can't get much more generic than that) but
the cost involved forces me to find some reassurance it will be a
worthwhile investment.

Investment? I think not. Studies show that adding minor external
details such as new trim, doors, etc. rarely return more than 50% of
their cost when the home is sold. So if you like the shutters, then go
ahead and install 'em. But although they be a sensible expenditure of
money for you, they aren't a good investment in the classical sense.