It's obvious the other gulf carriers will be cheaper when it comes to flying out of Doha because you will have to transit via their hub station. Qatar Airways offers you a direct route in most cases and saves your time, therefore their ticket prices will be higher out of Doha.

If you were staying in Dubai, the Qatar Airways fares would be cheaper when compared to Emirates, because Qatar Airways, won't fly you direct out of Dubai to any destination, you would be routed via Doha.

As far as the service goes, I will refrain from commenting on that bit :-)