Asim Hussain, the top energy adviser to Islamabad, said natural gas from Iran is nearly 30 percent cheaper than its domestic equivalent.
At those prices, Pakistan stands to save $5 million a day if Iranian gas is used for the generation of power, Pakistan's Dawn newspaper reports.
Negotiations for the IPI pipeline have limped along for decades. Iran and Pakistan in June signed bilateral agreements on the pipeline, though pricing terms and insecurity along the intended route continue to plague development.
Pakistani lawmakers have considered a variety of alternative routes to allay security concerns, though those options have sparked renewed internal debates over the timeline for the pipeline.
Iran will supply more than 750 million cubic feet of gas per day for the Pakistani generation of some 5,000 megawatts of energy under the terms of the 25-year contract.
Pakistan is looking for a major economic boost from the project, with oil and gas reserves in Baluchistan province expected to attract investors to the deal.