you're dreaming if you think anyone will buy Pakistani SAMs, go on, who? Turks have SAMs for sale, the UAE makes some great missiles, GCC and Africa is covered unless somehow we can come up with an exceptionally good product which is unrealistic really for us.
On top of that, as a poor country, long term investment is not something very significant as lifecycle costs usually are less important to poorer nations than the upfront sunk costs. We cannot afford them. If we saw it as being economical we would have undertaken the AAM project after the feasibility studies in the 90s.