Not all users are willing or can afford to buy nice third party airports but are able or willing to pay a small amount of money to use that airport for a small amount of time, e.g. 24 hours. Think about doing a world tour, or visiting a place you do not intent to go often en still would like to get the best possible experience.
As a side effect to this request this would also open up try before you buy functionality but you pay a small amount for it.
Functionality could include tracking of usage so that after x user payments user has paid full price and becomes owner of the airport package.
Link to the discussion thread related to this wish list item: Add option to pay per departure / landing for using 3rd party airports