How many vials?

Toomoms

I'm wondering, how many vials do people buy on average per potential child? I know this number could probably vary a lot based on unique fertility situations. Just wondering what everyone is planning on buying, and what their particular circumstances are/reasons for their number of vial purchases. My doctor told me about 3 vials per child, to give about 3 chances of pregnancy per child. I see many posters on here trying to buy vials for future siblings, and I'm hoping to buy enough so that isn't an issue for me. I saw another poster is buying 20 for 2 children! Is that the norm or on the high end for the average person here?