It isn't just "goods" that this applies to.
Have a look around this forum and you will see plenty of "Where is the cheapest IDC", "I want a cheap DM Course" threads.
Value is one thing, and we all like value for money, cheap doesn't always get you that value
I agree, and it's not just the pro-level courses this happens to. It starts with the Open Water courses and snowballs all the way through the curriculum. Here in Asia there are hundreds of dive students signing up for classes every week who select their training exclusively on the basis of price.
That is a very short-sighted approach to making a decsion, though. The expression "value for money" does not mean the same thing as "cheap"; it means "high quality at a fair price." Too many scuba students look for the cheapest course rather than finding the one that offers the best value for money. It's a kind of a mindset that doesn't cultivate excellence, but rather only corner-cutting.
For example, a school that only allows instructors to spend three or four hours in a pool with up to 8 students in a group, or that races through classroom sessions with the instructor reading the powerpoint slides aloud to a nearly comatose group, or that takes students on the minimum dive profile for a dive to count as an open water training dive (5 meters, 20 minutes) for each of the four open water dives isn't conducive to providing a quality course. But those are all ways to cut costs in order to reduce the course fees....
While it's possible to pay premium prices and get a crappy course, it's virtually impossible to pay bargain basement prices and get anything
but a crappy course. In other words, a product is worth no more than what you paid for it--if you pay peanuts, you get monkeys.