I would say they are probably much cheaper to operate than the M1. The current military guys in Iraq are probably used to operating Soviet era tanks anyways. You really need a well trained crew to maximize the M1.
Due to cultural disregard for technical skills, Arab militaries tend to do poorly at maintaining and training with sophisticated military weapons and equipment. Despite performance below that of US and West European designs, rough and ready Russian weapons and equipment are therefore often more suited to Arab military thinking and practices. In addition, Arab militaries require large contingents of foreign experts on contract to keep their kit running properly and to train their troops in its use. In choosing Russian tanks, Iraq is also expressing a preference for Russian contractors over US contractors. And it also matters that, unlike US and West European suppliers, Russia is willing and ready to pay illegal commissions and bribes to sell their military gear.