My daughter was full-time eced since about 6 weeks, and we still had 36 prefolds & 6 covers for her and used them all, lol. I am of the mind that it is better to have lots of diapers on hand than to have to worry that if I do not wash them right this minute, I will run out. We also never did nakey time, so there were LOTS of changes (changed w/ every pee, or as close to that as we could). Even when dd stopped pooping her pants, we still needed all those dipes.
Our younger baby stash now consists of 24 nb prefolds, 12 nb/small fitteds, 6 nb wraps, 3 nb wool soakers, 36 infant prefolds, 6 small wraps, a bunch of ss waterproof trainers, regular trainers, a pull-up cover, and assorted wool soakers and wraps. This will be our fourth eced nb & I can confidently say that YES we DO use all these diapers over the first year!
DD (4.25.08) DD (4.23.10) DD (10.13.12)