Here's how I rate the online stores that I use, Amazon & DD (Deep Discount)
AMAZON: #1
I rate their Cust Svc as the best with returns/exchanges for defective DVD's. I've been an Amazon customer since '04 when I started buying online.
I like their online shipping/return printable forms with free return shipping. They have also accepted any return-for-exchange item from me regardless of the expiration of 30-day return time window.
They ship my items in boxes (vs envelopes) more than DD does, although that has been more even between tham and DD recently.
As far as pricing in general, I've noticed that over the last couple of years, their pricing has been as low as DD's pricing or is less than them with a lot of their TV/DVD releases, in particular with new releases. DD will carry lower prices for some of their catalog titles vs new releaase price points.
DD #2
I started out in '04 buying from DD almost exclusively but after Amazon started lowering their prices overall, I don't use DD much except for their semi-annual sales in June and November.
The only problems that I've had with returns for exchange is with DD. They don't offer free shipping with an online printable return shipping form as does Amazon. I know that one can get free return shipping by either e-mailing or calling with their PDF file label that they send out, but it requires additional contact by the buyer to get that from them.
The only "snag" that I've had with return for defects was at DD. I sent a movie DVD back for exchange and never received the replacement. DD claimed that the never received my return shipment. I suppose that may have been true but that's never happened with Amazon. The thing that bothered me about the incident was that DD didn't consider the customer's buying history with them and wouldn't work with me on the issue.
DD consistantly ships in envelopes (vs boxes) and that contributes to a higher rate of damaged DVD's in transit.
DD's strong point is their free shipping regardless of the order amount. However, I almost always get Amazon's free shipping since I wait and order from Amazon after I have the min $25 free shipping qualifying total before placing the order.
Because of these issues, I usually only buy from DD during their semi-annual sales.
As far as other online stores, in my early online shopping days, I did shop around more for the lowest prices, but I found that it wasn't worth my time to spread my buys around with several stores vs staying with a couple of stores, Amazon and occasionally DD. I'd rather keep my DVD buying in a couple of stores vs several online.
I have used DVDPacific a few times and depending on the studio (ie Timeless), they can have the lowest pricing available. They didn't include free shipping the last time I checked with them.
I'm nearly a 100% online DVD buyer. I almost never buy from local stores. I have found that the online convenience, along with the nearly always lower price, plus the savings in time, online buying is the way to got for me.
The advantages (imo) in local store buying are the browse'ing in, say, a Walmart discount bin or a trip to a local Big Lots store for great deals. Also, a local store will offer a no-wait purchase for someone that doesn't want to wait for shipping times. I imagine that the return/exchange is more convenient vs online returns. That said, I haven't had to return many of my TV/DVD's for defects over the years so that advantage is not as important to me.