I dont know whats your problem with Iran, but their gas isnt more expensive than others (like Russia), and the cheaper deal with PGGC you refer to comes with conditions, i.e. Pakistan cutting off ties with Iran. While you may be fine with it, but this is a very short-sighted policy. What would happen if US would sanction Pakistan in the future? PGGC would immediately suspend oil and gas exports to Pakistan, Iran is cut off by Pakistan itself, what then? Pakistan would be screwed.
Learn from China, they are importing from everyone, and despite of PGGC "cheap deal" offers, China imports from Iran at the record levels. Because they are smart enough not to put all eggs into one basket.