What's the unit cost of a nappy in your area? Here it's like €0.05 each, so monthly maybe €50 max incl wipes. I'll have to actually measure how much we use in a day though.
However there's a two-for-one at my local stores, so in reality we pay more like $20.
[1]: https://www.libero.com/product/touch-open-diaper/touch-4-ope...
We go through maybe 5-6 a day for our 6 month old. The number I was comparing was probably when she was newborn and going through 10+ diapers a day and requiring multiple diapers per change because she'd pee or poo on her new diaper while changing her. We've been using cloth diapers since she was 1 month old.
We do keep some disposables on hand when traveling and just in case we forgot to do laundry or whatever, but I think we've maybe just used 3 or 4 in the past 5 months.