can some one explain to me what is cost of stadium expansion per seat?

This is ridicilous that as more money I invest cost per seat is higher....if you don't belive me try to build 1 seat and for example 15 seats and you will see that price is variable

you can not belive me too, but there is a small difference between building up cost of stadium FC Loosers (1000) and ie. Barsa Camp Nou (over 99 000)...