From what I have gathered, I think the more stopovers you have during a flight, the cheaper the fares are and non stop / direct flights are always expensive. Flying from Dubai to London is cheaper than Doha to London bcoz the passengers would have to stop over in Doha, wait in the transit lounge, spend few hundred riyals in the duty free and then get the connecting flight to their destination. It is always the case, direct flights to any destination by any airline is always more expensive.