Nasrudin had so much against his donkey that the obvious thing to do was to sell it and get another one. So he went to the market-place, found the auctioneer, and gave him the donkey to sell. When the animal came up for sale, the Mulla was standing by.‘And the next lot,’ shouted the auctioneer, ‘is this superb, unequalled, wonderful donkey. Who will start the bidding at five gold pieces?’
‘Only five for a donkey?’ Nasrudin was impressed. So he started the bidding. As the price mounted higher and higher, with the auctioneer singing the praises of the donkey at every bid, Nasrudin became more and more anxious to buy. The bidding finally settled down to a duel between the Mulla and a farmer. At forty gold pieces it was knocked down to Nasrudin.
He paid the auctioneer his commission of one third, took his share of the money as the seller; then he took possession of the donkey as the buyer. The donkey was worth perhaps twenty gold pieces. So he was out of pocket: but he had bought a donkey of whose merits, as he now realized, he had been ignorant until they had been so glowingly portrayed by the town auctioneer.
‘I never miss a bargain,’ said Nasrudin to himself, as he walked home with his prize.

The Pleasantries of the Incredible Mulla Nasrudin Idries Shah, Octagon Press