I have purchased gear online, my BCD, regs and computer specifically. My LDS, who is also a major online vendor, could not or would not touch the price offered by another online (with store front) store. I purchased the equipment after verifying with the manufacturer they’re an authorized vendor and continue to support two LDSs in my area for other items (my wife’s gear, since she’s not "off the rack" as it were).
Would I do it again? In a heart beat. Do both LDSs price match online? Nope. One, who I like quite a lot, gives the hackneyed line that "our prices are the best you’re going to find, so we don’t need to." Needless to say, they’re wrong on that count, but something can be said for extremely friendly service, and remembering someone who was in for 15 minutes three weeks prior, by name. The other shop? They will match in a heart beat, but they can be a bit harried at times and don’t always remember you unless you make a lot of purchases from them. Doesn’t matter though, as I said, I still prefer to shop at either of them but will shop online on occasion.