Funniest auction story I ever witnessed was a gallon of Roundup about twenty years ago.
I saw a guy bid that gallon up to almost two hundred bucks before he won the bid. As he walked past me with his prize I noticed the label said "Lawn and Garden". It was prediluted and ready to spray.
At the time I was paying $37/gallon for super concentrate out of the bulk drum at work.
The guy actually had about a buck worth of chemical in his jug.