So here's an example of how this works generally. No one company makes a complete platform. Different things come from different organizations. Take the F-16's, it has GD-LM as the highest level organization, but its engines come from GE, its avionics come from multiple organizations (too many to list) and combat systems from Raytheon, BAE, GoodRich, etc, etc. So airframe to radar to combat systems to the engines and down to the bolts, you have many companies involved.
Now the F-16's or any other defense articles are sold as a package and by getting approvals from the government of the United States. The government sort of controls and backs up the transaction (through different channels, such as FMS, NATO, etc). So you have the US gov't involved, governing and controlling what package, deal or equipment is given and on what terms and conditions. Within the contract, usually, the organizations offer post delivery maintenance services or support contracts. Now you can add whatever provisions to that (as long as they are agreed upon by all parties). That also has a clause of providing maintenance or support in the case of damage (NON war related) like floods, accidents, terrorism, etc.
Under a scenario like this, say if the contract is valued at $ 800 million, the buyer will pay $ 50 extra millions to cover these rare scenarios (just making these numbers and details up for explanation). Now if these contracts are for 5 years and nothing happened, the seller gets to keep the extra $ 50 million. If something happened, they'll fix certain equipment for free or for a small price, plus they'll give you labor for a reduced rate so that you may operate their product again that was damaged. This is pure business, remember, if they fixed a product and the buyer was able to reuse it....who will you go to for upgrades, additional equipment, training, etc? the SAME manufacturer for the life of that equipment. So they make money and it is in their best interest to help you operate their systems so you remain a customer.
In this case, no one imagined that the these radar planes will be targeted. Let alone getting targeted inside a highly secured base (Still beyond me to tell you the truth). So if this was a $ 1 billion deal, may be 15-20% may have been asked for these support contracts. Since no one realized the perceived threat, they didn't buy into the 15-20% of $ 1 billion as they thought the money would go to waste as these are highly secured assets and only danger to them was through the war. Turns out inaccurate, doesn't it.
Now, if you want this repaired, everything will cost you full price. In fact Saab 2000 was a discontinued or older model. So for it's support, the price may be 1.5 times or even double as labor supporting the older environment is rare to find. Another example is, how many people run Windows 98 today? Probably very few. So for Microsoft to help support a customer with such an older platform, it'll find contractors that'll be rare and more expensive as it's a rare commodity. Same concept applies here. Combine the labor, equipment and repair cost....it'd be as if you were ordering a brand new AWACS on a brand new airframe and that makes the whole deal super expensive from a financials' standpoint. Thus the decision to write it off.
Another thing is, the Chinese AWACS are there. Now having experience with Western AWACS, the PAF will ask or work with the Chinese to add certain features from the Western AWACS. Making the Chinese option very similar to the Western ones. So...why spend so much more money on a Western product to repair and fix, when you could theoretically get another Chinese AWACS with similar capability for half the price and a new / less used airframe too?