Not weighing in on price, but I'll say from experience, using a controller with paddle buttons and remappable controls is game changing.
Anyone that's used kontrolfreex knows that a simple thing like changing the height of a stick to provide more sensitivity can change your play - having the ability to quickly access buttons that are normally (stupidly) hard locked to bad configs changes games.
Best example is jump/crouch/slide in games that don't offer bumper jumper style configs or require you to move your thumb from aiming to slide or crouch. You can continue to aim and shoot while jumping or sliding with paddles.
It does matter, and it does affect your play.
Unfair advantage, well, I'll leave that to forum arguments and keep using my custom controllers

My kb/m setup is sure as hell custom.