It would be really interesting to be able to determine a "hype constant" for each type of computer sold on ebay. taking into account rarity, original price, software availability, features, age, originality, and final ebay price.
The sirius 1 must have a tiny hype constant, as there seem to be 6 of them, and the guy who copied me the system disks for mine can't get more than about £30 for his (complete with manuals etc).
The asr33 teletype must have a tiny one, as the one I was watching went for £40 even though it's a superb bit of hugely complex kit, and they don't come up for sale very often.
And the ZX80's must be huge, because they're still selling for £150 even though they're made of chocolate box liner, and the software is horrid, and there's at least one-a-week on ebay so they can't be that rare.