When to consider IUI/ IVF?

We've been trying for 2 years. All labs cleared, only issue is my PCOS which has no other symptoms except those immature eggs that can be seen on the scans. We' re both young. I still ovulate on my own and respond well to

fertility meds. I don't know why it is still not happening. It hurts me that I am even asking about IUI and IVF because we still do not have money to cover it up if in case that's our only means. We both have a stable job that pays well but no insurance will cover it for us and it is really expensive in our area.

You think I should be thinking about these or move on to a full course of 6 cycles of letrozole? I've only done 2 so far.