Airline ticket prices have been highly individualized for at least a decade. I live a nomadic lifestyle and I'm often traveling with friends from various countries. We can sit next to each other in the same café and search for the same plane tickets on the same website at the same time, and get entirely different price offers. This is one of the reasons that I never buy plane tickets without using incognito mode or some sort of private browsing, but even doing that affects the price that you're offered.
I've also heard that depending on what country you're buying from the price changes, but using VPN I've never been able to replicate the results. Pricing based on individuals sounds illegal.
It's definitely the case that a round trip going from A to B to A can have a very different price than a round trip going from B to A to B using the same routes.
