Earlier quoted context omitted.
I just had a kid 2 months ago, and 12 changes a day doesn't seem all that unreasonable for a newborn. At our one-month checkup he was averaging 9 pees & 5 poops per day - several of the poops were doubled-up where he also peed, so a dozen per day is about right. It's dropped a bit since, but instances where a single changing results in multiple diapers used (eg. he shits the table right as I'm getting the new diaper…
Not everyone has the ability to buy in bulk. They are considerably more expensive buying them 12 at a time at a corner store.
Buying in bulk (200 pack or so) easily gets you at 0.16/diaper or below. And even lower if you look out for deals.
And assuming you need them now and don't have money for bulk buy, a 27 pack at walmart for off-brand is $5.41 at the moment. ( ~0.20/unit )