beiker on "How many vials did you order at once?"

I'm a little confused. I was going to order 6 vials of donor sperm and have them ship 2 to my RE at a time (they do 2 days of inseminating) If I were to get pregnant the bank would refund me 50% of the leftover vials or I would have them for a sibling if I kept them. But I am now thinking that I should order 8 vials because I would want to at least try 4 iui's before moving on to something else. But isn't it risky to order that many right away what if the sperm turns out to be not so great and I have to try a different donor? I also don't want to run the risk of losing out on the sperm if I don't orer enough right away because I really like this donor. What have some of you done? Thanks