The Intel 4004 is probably worth a bit as well.....being the first uP.
You could have sold an original 8086 CPU to NASA a few years ago for use in the space shuttle program! It seems they had to use old technology CPUs because of the exhaustive quality control regime involved in putting a shuttle together.
Amongst the 'old crap' that I have discarded and now regret is a Texas Instruments SR-71 (I think) calculator (it did square roots!) and a HP 41C which I didn't intend to dump, but went missing during one of my relocations. I've still got the programming cards for the magnetic card reader, useless as they are!
There is a MicroBee community out there as well, determined to keep Australia's own PC alive.