I did a guarantee cycle. We had already spent lots on OE cycles so there is no way I wanted to spend money on a DE cycle and not have a guarantee of a take home baby or a refund.
How many fresh cycles do you get for $30,000? Does that include donor compensation, donor screening, any administrative fees? My guess is you will also have to pay for meds for you and the donor in addition to the $30,000. You may also have to pay for additional tests on yourself and a mock cycle. Chances are you will get pregnant on the first cycle so you will have paid more than necessary. But don't count on it working the first or even second fresh cycle. The peace of mind in knowing that you will get a refund is huge and I think well worth it if you can afford to pay for a guaranteed plan.
In the meantime good luck with the IUI's. You could get lucky.