Well in keeping with this conversation, what is the stupidest thing anyone has ever bought from you (aside from a Robert Graham shirt)?
At one time I has several garbage bags full of used packing peanuts. I would suck the air out of the bags with a vacuum cleaner and store them in the garage. It got to a point where I just had too many. I figured, sellers would buy new peanuts online for their shipping supplies. Have you ever seen how much they cost? It's ridiculous! Anyway, I sold a large box of USED packing peanuts for around $20 plus shipping.
+1 I have picked up a few free bags worth on Craigslist myself.