Wow - "the trick is to find the lowest price and then quickly place one's order before that price goes up."
That's one of the primary scam tactics: "If you buy in the next 30 minutes..." or, the used car sales: "I won't be able to give you this low of a discount tomorrow..."
I would hope that this gets a lot of backlash and never becomes standard practice. In some senses, though, it sounds like a bad deal for the seller. If you can get the product in ten other places, raising the price because you've been looking around for it would more likely drive business away.
I've hear rumor that some domain registrars will take URLs that you search for but don't buy and pull them off the market for a few days. During that time, the registrar would allow you to come back and buy it, but now at higher "someone else owns it" price. That's a similarly bad idea.
Reminds me of a visit I made to Zimbabwe a few years ago in the days of hyperinflation. I needed a replacement fluorescent tube and priced one at a local electrical dealer. The price seemed a bit high so I later got a couple more prices in town. The second price was the best, so I returned there the next day, only to find the guy had put the price up and wouldn't budge. I ended up getting the tubes from the first guy (who hadn't yet increased his prices}. You had to act quickly in those days. Fortunately Zim now uses the US$ and prices are pretty stable.
It's possible to avoid this by disabling cookies in your browser, using private browsing or running a different OS+browser in a VM such as VirtualBox. Your IP address will be consistent, but their cookie tracking will be thwarted.
I think that we all experience this effect when we buy airplane tickets online. By the time that you check (with your spouse or colleagues) that the schedule and price will work, the price has jumped. It seems to me this happens in minutes during a single browser session.
I have a friend who lived through hyper inflation in Argentina. They had a "joke" that went- Is it better to take a bus or a taxi?- A taxi because you pay at the end of the ride (when the money was worth less).
It is anecdotal evidence to be sure, but when I was researching gifts on Amazon just prior to the holidays, many of the items I was interested were listed at prices significantly higher than what people reported paying just a few weeks prior. So do everyone a favor, when you buy from Amazon, put the purchase price when you leave feedback on the product, in that way future buyers can see what kinds of games these folks play. When people automatically assume they are getting the best price on-line, they might be shocked to find the exact item at their high-end local department store for less than Amazon. As always, buyer beware. Don't get me wrong, I love buying from Amazon, but don't do it blind.
I must admit that when I think of all the money I spend on Amazon, I would sot of hoped they (their system) would give me a good deal rather than saying "Well, he spends a lot so let's charge him more!"