You just confirmed there is a preferred economy and economy. I just booked economy flights for my wife and all the seats were the same for the row, There was then an up charge if she switched to preferred economy.
I regularly fly and I can book the preferred economy at no charge and if I upgrade to economy plus there is a single charge regardless of seat in a single row. The only times that is different is for exit row seats. Those are classes as preferred economy but more than the other preferred economy. Last year when I had gold status I could book economy plus at no charge and it was the same regardless of seat.
I literally just fucking looked at my wife's economy tickets for a flight she has in two weeks and it's the same regardless of seat in a row. In fact all the rows are the same as long as they say economy.
Arguing with me on something I am 100% fucking right about and can fucking check is the stupidest thing I've seen on this fucking website. Do I need to take a bunch of screenshots for you fuck heads to understand something you know nothing about?