i have seen a few of the pacesetter headers for the mk2 82-86 supra inline six, and it sells for roughly 100usd. the quality of bending is good, and the flow pattern is well thought out, but the metal is very thin, or, in other words, it is very light for maximum performance.
HKS exhaust are the same. they use really thin wall mild steel tubing, which is great if you live in arizona, but not so good if you drive through lots of water, or heaven forbid snow and salt! My brothers HKS exhaust lasted only 2 winters before pieces started falling off, and he paid close to a thousand for a cat back back in the day.....
Sometimes you have to draw a line between getting something thin that will wear out faster, but be lighter and better in the short term, as oposed to something beefier, which also weighs more, costing you power in the short term, but having a product that lasts a lot longer.
It's like that joke about the 2 bulls, one old, one young, standing atop a hill, and wanting to go down and screw the lady cows. the young bull says, "lets run down and get us one of them cows". The older and much wiser bull says" Lets walk down and get 'em all!"