Nb use only 1 pack. S use about 3 month. Daily 7 to 10 pieces. M use for about 6 months. Daily about 4 to 7 pieces L currently using. Daily about 3 to 5 pieces.
For newborn I bought small enough 1 packet first in case baby sensitive. When upgraded to s size, I will buy 3 packet at a go as usually is cheap in bulk.
I also initially stored a lot of diapers. But with the growth of the baby, the diaper size changed quickly.