The reason why brick and mortar stores are dying out

I'm traveling, currently in Sydney, and needed a new SD-card because all my cards are full and I like to keep them as a backup for the pics I put on the MBA. So I walk into the first camera store I see, with my OM-D dangling around my neck and ask the guy at the counter what their cheapest offer for a 16GB card is. He pointed at my camera and said "You don't want a cheap card with that camera." I said, "Yes I do", irritated, because I've been shooting with class 4 cards just fine for the past 2 years. He produced a 16GB class 10 card for a whopping 50$ AUD. Saying "We don't sell any cheap crap cards here. If you want that, you need to go to Dick Smith or something like that (it's a electronics chain here, not an insult). I said, yes, that's what I'm going to do.

At JB Hifi I got my usual Sandisk class 4 16GB for 16$ and could have got a class 10 16GB for 32$, too, still 18$ less than what he offered.

So getting doubtful advice from an "expert" at the brick & mortar store comes at the price of a 200% surcharge? If so, no wonder they're slowly fading into oblivion.