I was just in BKK where the duty free shops there were selling two (2) 1 liter bottles of 12 year old Chivas Regal with a "free" 20cl bottle of 18 year old Chivas for 2000 Baht, or about US$62.20. The going rate in most duty free shops for a liter of 12 year old Chivas is on the mid-30s and higher on the planes. So this was a very good deal.

Duty free prices vary greatly around he world and on different airlines and also by commodity. It probably has much to do with the shop's overhead costs as it does with the price and promotions of the commodity itself.