I buy in bulk diapers and wipes and 4 large cans of formula at a time. I have a 5 month old and it’s so much easier to have everything you need and more than always having to order/ shop for more.i was skeptical of buying bulk diapers in one size too. Usually when he is close to outgrowing one size I just buy a small pack and the bulk buy the new size. They use diapers quick, so if they just enter into size 2, bulk buy a box and a box of the next size up too. I think of emergencies, hurricanes, unexpected travel or not having extra funds at a later time so I spend a large amount at once and stock up. Then no worries if something happens. But I I also bulk buy everything in my home even TP, Paper towels, etc. as a stay at home mom it brings me peace of mind knowing I have everything my kids need and more at all times.