One has to keep in mind that there is always a trade off in the aircraft design. A bigger engine means more thrust but also means more weight thus less agility. Same thing applies to avionics package and more hard points.
J17 is essentially a low cost/ lightweight agile fighter with limited range and endurance. I am not referring to ferry range but fully loaded low-low-low range. Regardless of the wishful thinking, ground realty is that JF-17 would be at a serious disadvantage in a hostile environment patrolled by SU30- Mk1 and Rafael. Therefore JF-17 is more suitable for use within a short distance from friendly territory where, in the event of being out gunned, help can arrive quickly.
In my humble opinion, 150 aircrafts or 9 squadrons of this type are sufficient for PAF needs. That is 3 squadrons each dedicated to air to air, air to ground and defending the 200 mile economic zone in the anti- naval version.
Interdiction/ ground attack deep inside the enemy territory and providing air over to the ground forces in the enemy airspace should be left to heavier longer range aircrafts such as F-16 & J-20 as these aircraft have better chance of survival. Therefore rather than buying JF-17 beyond Block III, funds would better spent on additional F-16 block 52 and/ or J-20.