JF-17 is delayed even by PAF's own schedule. Whatever internet theories we might come up with regarding PAF not liking J-10A and requesting for J-10B, the J-10A has the West scared, comparing it to an early block F-16 which is currently going even further upgrades to be comparable to Block 52. Pakistan jumped on the wrong horse.
I agree with you, PAF might get a cost-effective replacement for older J7 an Mirage fighters, but was that enough foresight?
If they had joined the J10 development (if it was proposed from China, donno about it), they might get a fighter with a bit more operational and unit costs, but also a fighter that is in the F16 class and as capable, maybe even better!
Some say JF cost only around $20 millions, but J10 around 40, but they forget, that this is the export price of J10! If PAF had joined the development, with the same ammount of investment and production in Pakistan...like they do with JF 17 development, J10 would be cheaper too.
It still would be costlier than JF to procure and to operate, but that means only that you can buy less. Instead of the first 2 batches of JF (50 + 100 if I'm not wrong), PAF might only be able to procure and operate 100 J10A. So instead of the 250(+) JF in total, maybe only 170(+) J10 right?
Although in numbers they would be slighty less, wouldn't the benefits in quality be worth it?
Instead of a high/low mix of around 120 J10/F16 and 250(+) JF17, PAF could also have one level of 290(+) J10/F16 right? J10 in these high numbers for air superiority and 60 F16MLU/B52 with the advantages of the US weapon pack in the strike role, would be (imo) the cleary more capable and better combo for PAF.
I am not saying JF is a bad fighter, but there is a reason why many Pakistani members still hope for J11B, or even foreign fighters like Gripen NG, or even Rafale. Because as good as JF might be, it will remain only a low end fighter, while J10 could have been a cost-effective medium, or high end fighter!