If you are buying for a daycare or charity, or want premium/eco-friendly materials in larger quantities:
Often beats Costco on price-per-unit. A size 2 box may contain ~20 more diapers and cost ~$3 less than the Kirkland equivalent. They also carry a wider variety of name brands in-store than Costco. BJ's Wholesale Club Warehouse club Open7005 N Davis Hwy where to buy baby diapers in bulk
: Offers a standard 5% discount on subscriptions, plus an extra 5% for Circle Card (formerly RedCard) holders. Target is famous for its "Spend $100, Get a $20–$30 Gift Card" promotions. If you are buying for a daycare or