TI vs IUI

This cycle there was miscommunication and we did a TI cycle instead of a IUI cycle. We were looking at the doctor’s notes from that appointment and saw they had written down the following:

“With OI/TI the change of pregnancy increases to 11-12% per cycle. OI/IUI shows a cumulative rate of pregnancy of 31% over 3 cycles. Recommended to patient to undergo OI/IUI for this reason.”

They had told us to do TI and we were good to go once she checked with the doc, and then left. She came back, really quickly said “the doctor says IUI has 30% chance of pregnancy, here’s our card, call us on CD1” and then left. Both me and my husband thought that was a “for future reference” fact since we’d asked about pregnancy rates earlier, not a change of plans. 😳

So anyways, my question is why skip straight to IUI if TI seems to have the higher success rate and is $200 cheaper each cycle? (Unexplained infertility)