Link Pharmacy doubles prices at OR Tambo

I stopped at Link Pharmacy to buy 10 Transact patches which cost around R180 at pharmacies. The price at the pharmacy in the general airport concourse was R287, R100 more than at other outlets. I was advised by the pharmacy to try the Link Pharmacy in the international departures area which would be closer to the normal price as it was \duty free\". The price for the exact same product was nearly R350, almost double the price than at outlets around the country. What a *******. How does Link explain this ridiculous mark up. Are travellers supposed to be wealthier than other South Africans therefore Link can jack up their prices even at Duty Free?"