I do believe 50 USD per person isn't that big amount, golden opportunity for the people to see the location through sky view, just like the birds ;)

The sightseeing flights will be available on April 21, May 5, May 19 and June 2. The airplanes will depart from the Terminal 2 at the Vaclav Havel Airport and the fare is symbolic - 950 CZK (40 EUR / 50 USD) per person.

I think you should also go to have a sightseeing flight Tomas, i wish this offer was given by the PIA i would have booked the tickets of my family ;)