What would cause it to corrode if its made from the same metals as the branded pipes?
Because it probably won't be made from the same metals. If this was 20% or so cheaper than Cobra etc, then I think the quality might be up there, just saving on labour by making them in Asia, but at less than half the price, something smells dodgy.
I've heard of companies selling S/S and aluminium as whatever grade, only for people to find out that they are infact a much inferior metal.