I think Suns will always be collectable, as they are
now. There are
some
weird things they have made over the years that people
seek.
Early machines from the 'workstation wars', Apollo and Tektronix come to
mind, may be of interest in the future. There doesn't appear to be much
on the technical doc or software side around for these. I tried
contacting
they guy who was working on the Apollo port for NetBSD to get the tech
info
he was able to collect, but got nowhere.
People seem to have saved the later SGI IRIS (3xxx series) though,
probably
because of the neat graphics demos.