Russian arms are cheaper, and the Russians (like the French) usually won’t impose embargoes on weapons for political reasons.
That said, I still think the Iraqis owe us some kind of repayment.
Russian weapons are not only cheaper, they are easier to maintain. Most 3rd world military do not have the technical base to maintain Western weapons systems effectively.
Our pay back in Iraq is our military presence in that country.
Iraq is the strategic high ground of the Middle East. A geographic barrier that severs ground communication between Iran and Syria apart as well as providing another front of attack into either state or into Saudi Arabia if needed.