While traveling on GT Road from Lahore to Multan recently, I noticed that the CNG stations situated on the roadside are all selling gas at different prices, ranging from Rs 35/kg to Rs 47/kg. When I enquired about their profit margin, they mostly said it was 'enough'. That means that there is enough margin of profit even if gas is sold at Rs 35/kg. The government should try to establish its writ over this mafia as well. -WASEEM KHAN, Karachi, via e-mail, August 23.