Why would they? It's not about what's new, it's about what's effective. And these tactics have been effective for thousands of years. Of course, they're more effective with tourists who haven't been exposed to this sort of bargaining before, and have been trained to smile, nod, and pay whenever someone tells them a price. Still, this sort of salesmanship is -- and will always be -- effective. Why? Because it's personal, and it's relatively enjoyable for both parties if done properly.
In fact, it's only fairly recently that this sort of haggling has stopped being the way you did all your shopping (at least in the Western world.) Probably until the late 1900s, you walked into a store and expected to haggle with the owner over the price of the items that you bought.
Knowing what it is when you see it does not make you immune to social engineering. The author knew right away what they were doing, but it still worked.
In fact, it's only fairly recently that this sort of haggling has stopped being the way you did all your shopping (at least in the Western world.) Probably until the late 1900s, you walked into a store and expected to haggle with the owner over the price of the items that you bought.