LKY: very informative article. Bear in mind though that many individual sellers on amazon could still be turning a profit.
I actually don’t always find amazon to be cheaper, especially if there aren’t many sellers of a particular item.
Funnybone: she shouldn’t have screamed at you. But you were definitely wrong for continuing to squeeze her after she gave you a great discount, and from the way you worded it like you had the RIGHT to get it for 18, not that she’d be doing you a great favor. Her overhead is probably high, you’re not paying shipping which unless it’s shipped through amazon and you spend additional 7 bucks there you’d most likely have to pay more than $2 shipping. You have the convenience of seeing, feeling, smelling exactly what you’re buying, and can take it home immediately. Plus, if you don’t like it you don’t have to pay return shipping, assuming they have some return policy. The only downside could be if it’s heavy/bulky to drag home.
From a halachik point of view, unless the amazon seller is Jewish, you are also most likely wrong. Read the last comment on this thread http://www.theyeshivaworld.com/coffeeroom/topic/buying-at-a-jewish-shop-vs-a-non-jewish-shop
You also have to think if you would manage if local stores are driven out of business, for example when you need something ASAP, or want to buy a few screws. (Personally, although I do it out of necessity, I feel guilty buying shoes online for my kids at substantially cheaper prices, although somewhat lower quality compared to local stores, knowing that if everybody did the same, I wouldn’t have where to buy a “first toddler shoe” which really needs to be fitted properly.)
Hope I gave you some food for thought.