Medicated cycle versus IUI

My husband and I went through all the fertility tests and everything turned out normal on both ends. We’ve been trying for a year and have had one ectopic. The doctor diagnosed us with unexplained infertility and suggested IUI with letrozole and the trigger shot. He said letrozole on its own would be a waste of our money and we should go straight to IUI. However, I ovulate on my own. Should I push to do a medicated cycle before we jump into IUI? Is the doctor just trying to make money off of us by suggesting iui right away?