Again, it depends.
First question. Has your DH had a normal sperm analysis? If that is a yes, keep reading.

If he has not been tested, go get him tested. If you are dealing with MF, no more than 2-3 IUIs.
Reasons you could do a few more tries than the average "3":
- You have "unexplained infertility"
- You are fairly young, so you have time
- You respond well to Clomid
Now, you have 80% IVF coverage. If you want to get down to business, I would move forward with that. But, even 20% out of pocket can be expensive.

and hope this just ends up to be a BFP at IUI #2.