I worked for airlines and one of the big 3 for many years. They have complex algorithms that try to determine the lowest price. They're competitive, and want to be the cheapest they can. They're not trying to "hide" any prices.
Doing what the author says will get you banned from the airline. If you don't fly the itinerary listed, they will tear it up in front of your face as it's in the terms and conditions.
My point: there's no real secret - the sites like Kayak and any ITA-based search product are pretty much doing so many creative things to minimize the price that it's rare to find an exception without cheating.
Finally, the pricing is crazy, but being in the tornado there's a method to the madness.
https://github.com/krickert/IPAddressZipCodeStateCountryLuce...
It downloads one of the many free DBs of IP addys and makes it into an index. You can do geo spatial searching APIs with IP addys.. Fun stuff.