From Private Eye issue 1198, this advert that appeared in the Galloway News:
"Parachute, used once, never opened, small stain. £50 ono."
Eeeeeeek, I say!
Then I thought, hmmm, I'm sure I've heard something like this before. So I did a little search and found this item, which says it was (surprise, surprise) a hoax. The phone number advertised is actually for the canteen at the Dumfries & Galloway College. The catering firm there said:
"people have phoned and asked to buy it for their mother-in-law".