I was at my friend's place swapping stamps and comparing my collection to his. Among his swans I had found what to my knowledge was a particularly rare stamp. On questioning him I discovered he had found it on a letter, dated many years back and addressed to his greatgranduncle.
After a long discussion he decided to let me have the stamp. It was not really the stamp I was interested in, but its value that attracted my attention.
The following day I found myself in front of a "shop". I entered explaining my presence. He studied it closely. For a long time he looked through various books and catalogues. After a great deal of time had passed he announced to me that he could find no indication of the stamp's value. But he assured me that if I came back in a week's time or so, he might he able to trace it.
The next week was a very anxious one for I was looking forward to the day when I had to visit the stamp dealer. Finally the day came and once again I found myself inside the "stamp dealer's shop".
He had a big grin on his face and in plain language told me the stamp was worth anything from £125 to £150. Of course I sold the dealer the stamp. I rushed off to my friend's place and announced to him the good news. I was going to give. him all the money, seeing it was really his stamp, but he gladly gave me half of the money for selling the "Rare Stamp".