We use target brand. I have the credit card and that makes shipping free and saves 5%. I've also used diapers.com and also amazon mom. Prices are always changing on amazon and diapers.com is more expensive so I've stuck with target.com up&up brand. I also use target brand wipes too.
It just depends on the week and the coupons available to where it is cheaper. I got diapers for less than 12 bucks for 144 size 3's in January. The sale was 2 babies r us boxes for 35 (17.50 a box) and I have the 6 dollars off coupon from the black friday boxes. Even without the coupon the sale price was 12 cent a diaper.
Per southernsavers.com a that is a great price at 12 cent
Broken down by size this is what we generally see:
Newborn: 13¢ – 16¢
Size 1: 11¢ – 14¢
Size 2: 14¢ – 16¢
Size 3: 16¢ – 19¢
Size 4: 19¢ – 22¢
Size 5: 22¢ – 26¢
Size 6: 26¢ – 30¢
Right now the same diapers are basically the same 27.99 a box x2 (required for deal) = 55.98 - 20 gift card you have to use later maybe on 2 more boxes = 35.98/ 2= 17.99 per box /144 diapers on size 3 = basically 13 cent a diaper. Just you have to roll that 20 off onto the next 2 boxes or a purchase of something else. You could put money onto a their diaper card and buy diapers with that it gives you more money than you put in but I am not that patient. I have had issues locally finding the right size because the time I had money was half way thru the sale. Who knows what they will do next sale on Feb 11th.
You can also go to sites like southern savers or hip2save and see what they say is the best diaper deal when you get money. Since deals change often.