In simple terms, its not cheap and not easy
On 3rd July 2012 we lost three lives and two Tornado aircraft, how cheap does it have to be?
Also, in view of the importance of having height information I would have thought that a simple call from Lossie ATC to Inverness informing them of the lack of Kinloss SSR information, with a request to keep a watching brief between certain times. On the other hand, perhaps pride got in the way.
DV