Diaper Stock Pile?

Just wondering if any mama's out there are experienced in diaper stock piles? This is my third baby so I should be! But have never actually kept track of how many we were buying and have never done a stock pile. I've seen a few guidelines on Pinterest but they seem to vary by quite a bit. We will have two kiddos within a year and a half so want to get a good pile going now since we'll have twice the expense for a while. If anyone has specific experience on starting weight, my smallest baby was 8 lb 3 oz. and #2 was so big NB size didn't fit and went straight to size 1! So I'm sure this one will be good sized too. Any input is much appreciated! 😊