Algorithms Are Rewriting the Rules of Prices and Wages (youtube.com)
Any specific pricing (specific price for an indivual, regardless of anything) should be illegal. It has a chilling effect on the economy. If I think a service will charge me more if I log into their website and it knows I want to use it, or I've paid more before, I will tend to be too wary to log in, which means I'll just use the sight less and do the thing less. I'm sure almost everyone's that way. But barring a law, there's every incentive for the companies to do it.