Numerous airlines serve Marrakesh airport. Don’t hesitate to search price comparison sites which in minutes will give you the prices offered by the different companies. Do the reservation simulations through to the end to get the real cost of your tickets (baggage supplements, bank fees, …) and in this way be able to book the cheapest on offer. If you can, book your tickets 2-3 months in advance and look at the airline websites that give monthly tables of daily rates. If needed, I am available with some tips that I use.