Take the ring back. Use the money as a cushion in case he can't find a job, or for the start of a house down payment if he does. Sit down and figure out how much disposable income he has on hand after 6 months of your bills are paid--make that budget together--and use that amount to buy a simple, well-made band in 18k or platinum, instead of the large low quality diamond. And if you find out he charged those rings--b/c how could he get 2 for 9k, no matter the quality compromise?--run like h*ll.
Example: if his monthly expenses come to 5k, including paying down debt, make sure he has 30k saved up. If there's more than that, you could use that amount towards a ring--though still risky, b/c of course you want a house downpayment, a nest egg, retirement, and there's the possibility in a recession that he won't get a job in 6 months. It may not seem romantic to think about this stuff, but a marriage is a financial partnership, and money issues are the #1 cause of divorce. If he's willing to spend 9k on a ring, you need to know that he's making a sound decision, because it's your future, too.