They just got conned by Indians is all. However, even historically speaking Sweden had very limited exports of its prior fighters as well, Viggen and Draken so with Grippen it is not completely a surprise. But as pointed out earlier, buying then would have dealt a killing blow to the JF-17...
Who are you kidding ... when do most Pakistanis pay taxes (sales tax not withstanding)
Why don't you try the same logic and go to your nearest police station and ask them to borrower one of their vehicles since you as a tax payer paid for it.