Tevasmurf is bang on the money by advising you to steer clear of internet sales. There are a number of issues when dealing with an online retailer as opposed to a local dive shop.
1/ Quality of the gear: It may be a reputable brand, but how do you know you're not getting gear with an issue, be it blemishes or even some damage, that is the reason why they can't sell in person.
2/ Are you actually getting what you're paying for? Counterfeit gear is on the rise. There's good money to be made selling sub standard gear that's fake.
3/ You've snapped a D ring or chest clip. Now what? Are you prepared to send your BC out for a few weeks, paying for shipping costs and the repair? The service is virtually non existent.
4/ Well golly, they advertised that BC as a large but you can't get it on. Not all manufacturers use the same guidelines as to sizing. One's large is another's medium. Now what? It doesn't fit.

Buying from a reputable local shop does a few things in your favor. You get to try it on, try it out, see it and inspect it first hand. You get to compare different manufacturer's gear right then and there. The gear in question will be exactly what you're paying for. The service is right there. Something like a D ring could be fixed in minutes, not weeks and sometimes it's free if you're a regular customer. You're helping to support a local dive shop, keeping money in your community and divers diving. That local shop probably does volunteer work for keeping beaches clean or dive sites safe. You also get to make friends with people that dive from that shop. Instant dive buddies and they live right near by. No searching on the net needed.
If you buy regularly from a shop or make large purchases there, chances are, you can swing some really great deals. I get a 15% discount on anything I buy at my local one, sometimes more.