This is an article from 2007 http://business.timesonline.co.uk/tol/business/industry_sectors/transport/article1591309.ece
Slots on Heathrow’s runways are the most sought after in world aviation. The airport’s two runways operate at 98.5%
capacity. The only free slots left at the airport are late at night, too late to be attractive to most airlines. Heathrow's owner BAA, was today referred by the Office of Fair Trading to the Competition Commission for an inquiry that could eventually lead to its break-up. BAA faces a separate Competition Commission review into proposed charges to airlines at its UK airports.
Slot-trading is regarded by some as illegal, but despite this there is a thriving grey market. Few deals are disclosed publicly, although BA has in the past given some details of its transactions. Its previous biggest deal was in 2003, when it bought eight pairs of slots from Swissair, the Swiss flag carrier that later collapsed in financial turmoil.
Airline executives said that the price paid by BA appeared cheap. “Paying £3.4m per pair (the normal method for valuing slots) seems a very good deal. Pairs have changed hands for £10m,” one said.
5th freedom rights are vital for fun game play, until multiple hubs are allowed. If they weren't allowed every airline based in smaller cities would be unable to expand after a couple of weeks gameplay