2.5 billion USD may be an affordable price for countries like Turkey, but not for Pakistan. Pakistan is poor and the rulers make it poorer.
While Army paid for LY-80 LOMADS (acquisition cost < 1 billion USD) from its service budget and development funds, PA or PAF may not afford off-the-shelf purchase of long range air defence systems without signing up for loans.
The roadmap should be development of an indigenous long range air defence system, comprising the vertical launch unit mounted on TEL vehicle, canisters and missiles equipped with active radar homing seeker, command and control, data links, power supply, etc. Long range AESA radars could be purchased off-the-shelf from OEM's like Leonardo.
This approach will save Pakistani tax-payer money from being wasted on funding ridiculously expensive weapons development programs of other countries and develop the local industry. It must be Pakistan first and then the rest.