DXB charges around Dhr500. FAC is around Dhr380 for a C172 once you get checked out. Microlights are Dhr300.
The airfield that i was talking about is Rabigh, its presently used by Saudia for its flight training school.
BTW, its around 50C in RUH at the moment, so bring plenty of sun screen
Enjoy,
Mutt