Today (22.3.2018), Mr. David Kopřiva, an appraiser, was a guest on a talk show Guest of the day on PrahaTV. He talks about beauties of philately, qualification terms for the world expo, recent sale of the most expensive czechoslovak stamp – granitic four with upside down overprint for 9,3 million CZK and the opportunity to see the iconic blue and red Mauritius during the PRAGA world expo.
The whole interview is accesible through this LINK (only in Czech).