LeisurePro are able to sell products for less than your local dive shop for a couple of basic reasons:
1) They access the 'grey' market which in practice means they buy stuff in bulk from places the manufacturers sell it relatively cheaply (e.g. SEAsia) and ship it to places where the market will tolerate higher prices (e.g. Nth America); and
2) They accept lower margins on the goods they sell as they have higher volumes. Pretty basic business economics, same reason Walmart is cheaper than your corner store. Reasonable to assume they also have a certain amount of supply chain power, meaning they can extract better deals from the manufacturers when they do deal with them legitimately.
I have bought a number of items from them including a BCD, wetsuit, camera and numerous accessory items and I can say my experience to date has been excellent. Stuff normally arrives within 2-3 business days (even with the free shipping option) and has always been in perfect condition. That doesn't mean I don't buy anything from my local store, just that more and more I'm finding it easier, quicker and cheaper to deal with LP.
There is a certain moral argument that says we should support our local dive stores as they are the lifeblood of our industry etc. etc. Much as there is a certain moral argument people should only buy locally made cars, eat locally grown food, reject Amazon in favour of local book stores etc. Each to his own I suppose.