I get the impression that support for older products is a rarity amongst all businesses not just in HiFi. The one exception that stands out in my mind is Naim Audio who still service their oldest equipment going back 50 years. Only when components become unobtainable, CD Mechanisms for example, are they unable to keep their old gear running.
Used PS Audio Items
Always checking for used equipment and have my targets on Hi Fi Shark. Every day there are many new listings of PS Audio equipment. Are people unhappy with their purchases ?