Book 'Bots Battling Builds Bizarreness?

Have you ever noticed that "Buy This Book Used..." prices from Amazon and the like are often bizarre? Often they're strangely specific -- "\\(43.72" -- and often they're insanely overpriced "Paperback 23rd Printing of Programming with dBase II: \\)1,234.56"

Jeff Duntemann thinks it's due to 'bots. If it's not, it's not a bad idea for a business:

  Register yourself with Amazon et al. to receive used-book requests   Set constant minimum_acceptable_profit_per_book   Set constant hoped_for_profit_per_book   Set constant cost_of_remailing   On receipt of used-book request{   check your used_book_quotes dictionary for a price   if you don't have a price{      make the same used-book request      record quoted price from other suppliers      set price = quoted price from other suppliers + cost_of_remailing + hoped_for_profit_per_book   }   else #You do have a price   {      quote price      if accepted {          sell, achieving profit >= minimum_acceptable_profit_per_book      }  else #not accepted     {         diminish price towards: quoted price from other suppliers + cost_of_remailing + minimum_acceptable_profit_per_book      }   }   }

The downside is that with multiple such agents in the system, you can see how "quoted price from other suppliers" would lead to a positive feedback loop.