You mean to tell me that given what a regulator is engineered to endure that shipping it via UPS or FedEx in a well padded box is going to somehow inflict harm on that regulator? That just makes no sense to me. Regulators may be life support equipment, but they are also designed to withstand an incredible amount more punishment during regular use than they will being shipped. Also, how do you think your LDS gets them?
I purchase the vast majority of my "stuff" online and have it shipped, and I say "stuff" because it is beyond more than just Scuba. I'm talking about books, electronics, vacuum cleaners, etc., etc. I would NEVER pay shipping costs that high. Rarely do I see them that high, but when I do I take my business elsewhere. Also, don't forget that at least here in the states the cost of shipping is typically offset by the lack of sales tax. Of course, we all meticulously keep track of our online purchases and pay the state the sales tax they say they're "due" at the end of the year when we file our state income tax. Sure we do.
I never place an order online until I have "batched up" enough items to make the shipping economical. Some online vendors still offer free shipping (Dive Rite Express) and the others I use all have very reasonable shipping charges.
In my experience, I don't think the argument of the cost of shipping v. buying at the LDS (and paying for the gas to get there and the local sales tax) really holds up.