Ivf medications

Hello all, my name is Princess and me and my husband are about to start our first round of ivf. We are in the preparation phase and I had questions about the medication. My doctor informed me that I can order anywhere but does not recommend over seas. I am in the us and found this website called ivf pharmacy.com. The menopur is my main concern where I am it’s about 6,000 for the 30 vials I need. However it’s like a little over 1000. So why is it an issue to order from there versus from within the states if it’s cheaper?