Regarding permits for Nar Phu Valley Trek, it requires 3 permits. They are Annapurna Conservation Area Permits(ACAP), Tourist Information Management System (TIMS), and Restricted Areas Permits. ACAP and TIMS permit price remain the same throughout the year. But Restricted Areas permit price changes according to trekking seasons. September to November, it cost USD 100 per person for 1 week and beyond USD 15 per person per day. Similarly, from December to August, it costs USD 75 per Per Week and beyond week USD 15 per person per day. All in all, being a restricted area, a trekking permit to Nar Phu is cheaper than Upper Mustang.