After reading all of the misgivings that people have toward their local dive shops, it just reinforces how incredibly lucky I am. There are several dives shops within about an hour drive from where I live, but two shops really stand out, one in Kitchener/Waterloo, and the other in Oakville. Both shops are far more interested in cultivating a long term relationship with their customer base than they are in making a huge score off of a single sale. Both shops are willing to say "Yeah, that'll work, but I think this would be a better option and it'll save you a little money compared to what you were looking at." Both are willing to say "No, I don't think you need a new __________. Give me a couple minutes & let me replace a part & let's see if that fixes your problem." (And I wind up buying a $10 part instead of a new piece of gear.)
This business model may seem foolish to some, but it keeps the customer base loyal. I would not hesitate to recommend either of these shops to people looking for an LDS. (In fact, at one time or another, I have recommended both of them here on ScubaBoard.)
So, how do I deal with online prices? I will research what an item costs online (converting that price to $CAD). I will then print out the page and take that into my LDS and ask if he is able to come close to the online price. In some cases, the answer is "No, Hoag, I can't touch that price, but thanks for checking with us." Sometimes the answer is "No, I can't match it, but I can come close. Here is the best price I can do." Sometimes, the answer is "Ya know Hoag, that's a fair price, but I think I can do a little better."
After that conversation, the ball is in my court so to speak, and I have to decide how much I am willing to pay to have the convenience of buying it at my LDS and maintaining that relationship.