I know this is a sore spot for you, especially after your recent experience with Sherm's. I noticed lately in my online shopping that DK runs consistently higher (5-10% on the items I was looking at) than the MSRP that's generally available. As you say, what you get for that is no-hassle (and no cost) returns. But then again, if you don't have to return something, you've paid more (thus in effect subsidizing DK's cost to restock other folk's items). EVERY retailer will have some cost to restock an item, some more than others. Some build that into the price and charge everyone a "few bucks" more, others only charge if you actually return it.
Guess it's like insurance: pay a little more and come up a 'winner' if you have to return it, or pay less and come out 'behind' if you do.
Same thing on the cheap shipping. Except for any volume discounts they get from UPS/FedEx, they're all gonna have similar shipping costs. They can identify them as S&H and charger accordingly, or they can 'hide' them in the price of the product. But either way, the buyer is going to pay.