A good rule of thumb is not to judge something until you've tried it. I'm not going to do that here. I'm not going to order from diapers.com, so I can't tell you about the shipping or the customer service. I simply researched price (because you know I love to save some money), and I'm going to share my findings.
First, Diapers.com; then, my local Target (come on, if you know me you HAD to know that was coming ;) ).
I have a coupon for $10 off my first order of $49 or more. I figured that diapers.com sold by the case so I figured that $49 would probably be spent quick buying in bulk. I'm wary of buying in bulk, because when it comes down to cost per diaper you don't always get a great deal. I decided to do my research and see what came up.
We use Huggies Pure and Natural diapers. Yes, this money-saving mommy uses the most expensive type of Huggies there is. It's a long story that has nothing to do with this entry so I'll save it. I was surprised to find that they sell P&N the same way as my Target store, or by the case. So I compared the same package I can get at Target (score!).
A 80 pack of Huggies P&N is $21.99 on diapers.com (that is the sale price, it says original price $27.99). This comes out to 27 cents per diaper. My $10 off is only good if I spent $49, so I decided to add 3 packs to my cart for a total of $65.97. Subtract the $10 for a cost of $55.97. Diapers.com gives free shipping on orders of $49 too. And, if I'm reading right, no tax for Texas (it had certain states on the list that had to pay tax and TX wasn't there). This comes out to 23 cents per diaper.
This week, an 80 pack of P&N diapers is on sale for $19 at Target. I also have a $1 coupon, and I get 5% off (You NEED a Target Red Debit Card people, I'm tellin' ya!). So my cost pre-tax is $17.10, with tax it's 18.51, or 23 cents per diaper.
So it's all the same... except next time I don't get $10 off at diapers.com. And last week at Target I had a Target coupon for $2 off and a manufacturer coupon for $1 off, making my tax-included price $17.26, or 21.5 cents per diaper. I'm not always lucky enough to be able to stack coupons but it pays off when I can.
If we compare sheer base price, Diapers.com sells the 80 pack for 27 cents a diaper (and, like I said, that says "sale") and Target sells it for 25 cents per diaper. Now you do get a $5 off per case loyalty bonus at diapers.com, which for the size one case of 132 diapers makes it $32.99, or 25 cents per diaper.
So from what I've found, you really can't save much by buying in bulk at diapers.com. I don't buy in bulk unless I'm going to save money, because I need something to make up for the sanity it's going to cost me when I'm trying to store 240 diapers. Either way, by big pack or case, you have to order over 200 of my brand of diapers to get free shipping at diapers.com. I'd rather pick them up 80 at a time.