Heard this on the TV show "Dave Allen At Large" years ago:

A gentleman attends a house auction and notices that one of the items for
sale is a large, colorful parrot, and he decides that he'd like to own it.

When the bird comes up for sale, the auctioneer asks, "how much am I bid for
this parrot?" and the fellow opens bidding with "Seventy five dollars!"

"Eighty!"  "Eighty-five!"  "Ninety-five!" go the next several bids, and the
fellow bids "One hundred ten dollars!"

Bidding goes this way for several minutes until the fellow finds himself the
proud owner of a parrot for $450.  He approached the auctioneer and asked him
"can the bird talk?" to which the auctioneer replied "Who do you think was
bidding against you?"