The (American) Antiques Road Show on PBS (US Public Television) has
run a number of shows which re-broadcast appraisal interviews and
follow them with current appraisals for the same items.

Many nice items loose value over a ten-year period.  Fine art, as
classified by the art dealers, tends to appreciate.  Nostalgic things
tend to decline.  A lot of stuff simply maintains its price, which
means a decline in real value.  On current appraisals, the experts
frequently say "a few years ago one sold at auction for $$$, but
today the value has dropped to $$."

On the whole, I think people tend to gravitate to things their
grandmother had in her house.  Few people of active collecting age had
a grandmother (or grandfather) who had a player piano, or even a fine
music box.

The markets for all collectibles are also being restrained by the
number of youngish people living with their parents, people living in
small apartments, and people moving frequently because of employment
changes or restructuring of domestic partnerships.

There is also the competition of high quality of new instruments.
I would as seriously consider purchase of a modern MIDI piano as a
roll-playing one if I was buying it to listen to music.

Wallace Venable