But unless you spend the effort to personally test those 2 cent more expensive parts, how do you know you are actually getting more for your money until after y

But unless you spend the effort to personally test those 2 cent more expensive parts, how do you know you are actually getting more for your money until after your or your customer's shit is broken? Even if you do test it, you might need to retest those same parts a year or two down the line as either your suppliers equipment wears down, or the skimp on QC more over time, or if they just outsource it to someone else as a middle man. There is a lot of room in there for people to get fleeced because everybody is playing the same game all the way down the line to the hole they dug the minerals out of.