Odd vintage computer sellers

[Jack Blake]

> I've been after a manual for months. There is one up on eBay for $520, 
> it's been there for months.  A few weeks ago the seller sent out an 
> offer to anyone watching, with an offer of $399, I sent a counter 
> offer of $99.  I just bought a copy that turned up yesterday for $20.
> Zane

I see the same thing all the time on Amazon and various other used 
booksellers, it's a malfunction of using an automated pricing system.  
My uncle has spent years importing college textbooks and explained it to 
me about fifteen years ago, the system is fairly simplistic and sets 
prices automatically based on other seller's prices.  The sellers have 
no idea what anything is worth, so they trust the automated system 
rather than the buyer.  One person comes in and prices an old manual at 
some randomized, arbitrary amount in the hundreds of dollars (or a 
computer in the thousands), and the entire market adjusts to selling at 
that price without any human interaction.  The systems then ignore the 
lowball prices set by sellers who run smaller businesses and need to 
move inventory or sellers who understand the actual value of the item.

This leads to situations where an old paperback about an obsolete 
programming language gets priced at $455 and a half dozen other sellers 
under-cut it by pennies.

If you want to see how this same sort of thing affects various other 
markets, look into high speed trading firms.