The Planes were exchanged while Air Marshal Waqar Azim was Chairman PIA.
It was rumoured at that time that the deal initially offered for one for one replacement including all spare parts and consumables. The initial deal was good for Pakistan, however in the end PIA ended up paying $120 million pl;us the Aircrafts.
Where the $120 million went is any body's guess. I heard this from a reliable source but I cannot confirm that PIA did in fact Pay $120 million plus the initial deal of one for One exchange.
If some one can shed some light on that deal I will be much obliged.