For Prime members only, Amazon offers the Pampers Swaddlers Diapers Size 3 180-Count Box for $24.88. Order via Subscribe & Save to cut the price to $19.90. With free shipping, that's $0.11 per diaper, $3 below last month's mention, and $7 under what you'd pay in-store locally.
Note: You must have Amazon Family to get this deal. (Most Prime members get Amazon Family for free with signup; however, some people sharing Prime benefits prior to Amazon Household may not qualify.) Be sure to cancel Subscribe & Save after your order ships to avoid being billed for subsequent shipments.