Being in Canada, things are a little bit more difficult for me. If I buy online from a store like LP or scuba.com, I have two options:
1) Have it delivered to an address in the US, just across the border. It lets me take advantage of any free shipping offers there may be. I have to drive down there, cross the border, pick it up and take it back home. I can either try to "smuggle" it across the border, or declare it and pay the local 13% tax/duty on top of the retail value, which is in addition to whatever sales tax the store already made me pay. Not a lot of people know about this option.
2) Have it shipped home. There's no free shipping, instead shipping is more expensive, and I have to pay the local 13% tax/duty plus some outrageous "brokerage" fee the shipping company charges on top of everything else. However, even with this option, stuff still comes out way cheaper than buying it locally from any of the 5+ dive shops that would be closer than the US border, sometimes less than half price.
If online retail of dive gear is such a great business that's able to put all the LDS out of business, why aren't there any competitive Canadian online stores? Sure, most of the dive shops here sell stuff online, but all for the same ridiculous prices as in store, and the selection is usually extremely limited. Amazon has some diving stuff for sale, but you gotta be real lucky to find there what you're looking for. I'd be happy to pay a little bit more at a LDS in return for the personal service they have to offer, but not twice as much. I don't mind for small purchases, but for more expensive stuff it makes a lot of difference.