The number of cloth diapers you need to buy is roughly proportional to the amount you'll go through in one day. So learning that babies typically go through 3X diapers/day instead of X doesn't actually change the cloth/disposable tradeoff.

That said, 30 seems high to me. Our kid probably peaked at about 8/day.

(We started with cloth diapers, but the amount of time washing them was just too high.)