If anyone wants a cheap ticket on AtlasJet Luton to Istanbul, I would recommend not booking on the airlines website as they seem to be more expensive than using Travel websites like Opodo.
I was looking the other day for a trip in November, and AtlasJet wanted over £170 on their website, bit on Opodo was £94 and was only £1 more than Pegasus from Stansted. BUT you get to choose your seat and includes food and hold baggage!