If he wants to sell 50% gear then i have no problem with that. Let's call a spade a spade though. Label it as such and sell it accordingly. I will always have a problem with someone mislabeling shit, not testing it an pushing it on end users. Next a guy comes back with bloodwork that stinks and the excuses come rolling out. We hear all the bullshit stories such as a traumatic family thing, being out of touch for extended periods, on a business trip, whatever.
Let's call it what it is, substandard gear and substandard service. If that is what people want and you can continue doing business then good for you. There are tons of note lots that do the same thing with cars for people that have no credit and payday loan companies charging 500% interest, preying on those that think they have no alternative. Just because it goes on doesn't mean it is right. It also doesn't mean that people will not call you on it and out you when the facts turn up.
I personally would be pissed off even if it was labeled correctly. That would mean twice the normal powder would have to be mixed to get the mg per cc you are shooting for, meaning 50% of the solution would be who the hell knows what. We are talking about China here right? I guess your trust level is far higher than mine.