This is utter nonsense. Justifications in favor of Iran at defence.pk are nothing more than laughing stock among the educated people.
If you had read my post carefully, Iranian public can't buy unlimited quantity of oil within Iran, lowest price is quota based.
Even if there's a price difference... crossing border with oil tankers and than it's open selling purchasing in Pakistan only hint at rotten state and social structure.
I personally would not buy smuggled oil, even if it is sold 10pkr /liter less than regulated price by state of Pakistan.
During Zardari era, Iranian oil and bitumen was sold openly in front of Pakistani oil refineries.
I don't know, what's the current situation but learning about such state affairs, only burn our heart.