To see, at London 2010, I bought the ASCAT stamp issued by the Monaco Postage Stamp Issues Office.
About the topic of this stamp: William H. Gross, businessman, collector in its own pasttime and generous philanthrop. As soon as he achived a fantasy of having a complete collection, he sold it in the benefit of humanitarian organisations. Last year, the association of philatelic publishing houses, he was honored by their award.
About my curiosity: at the OETP stand, the 1.35 euro stamp was sold 1.35 pound sterling. At an exchange rate of 1 pound for 1.13 to 1.30 euro, a small benefit either for the cost of being at the fair or to avoid huger postage cost to their clients.
The stand was located in a square room that completed the great hall and the catwalks. You could find the second café, the Post Office counter, Stamp & Coin Mart, Monaco and Australia, and some non European dealers.