I've got the same mass produced header also. Got it because it was a short 4-1 setup, and dirt cheap. So far minimal leaking. If it gets worse no big deal due to the price. I tightened the hell out of those slip joint bolts. I found if you tighten them a little for one, then a little for the other, and keep going until they are very tight it comes out ok.

I figure there is this one factory in China where these things are stamped out, and they just ship them to different wholesalers where they then put their own logo on it and such. It probably costs a lot less than we think for just the part itself. Then factor in shipping, wholesale... you get the idea.