Sometimes if it is just poor assembly quality you can patch it up yourself easily. If screws are unscrewing themselves out all that's needed is a little Loctite or lock nuts. The metal is still perfectly fine.
Sometimes it's just patents that drive up prices in the US, for some stupidly simple thing like a bike pedal patents shouldn't exist, and for practical purposes it would be laughable to have a patent on some low tech stuff like that in China.
Sure you can get various decent accessories from china, but for most of the basic maintainance you need to source proper components (drivetrain, brakes, tyres, suspensions) from respected brands. You can go to the LBS, let them do the work and pay a premium or you can do it yourself sourcing components online for half the price. You could also source the components to the LBS and do the work yourself but that's usually the more expensive solution. As it often happens the most ethical choice of willingly financing LBSs is only accessible to the rich.
Guess they're just a chinese integrator/reseller and quality may vary a lot among different products but I have to say I'm really happy with my backpacking bags (waterproof top-tube and frame bags) I got from them on amazon. I wouldn't trust them with anything "mechanical" though.
Pedals, especially flats (which btw are used by plenty of MTBers), are a breed of their own... they usually come from the same few factories and final price depends on who puts their logo on them. For a good while you could find the very same pedals from HT and from plenty of other minor brands for prices varying from 30 to ~150 euros.