As mentioned in the previous posts it seems like they don't offer any form of trade assurance... but then again none of these suppliers listing these mining products on Alibaba seem to offer any form of trade assurance, so does that mean that they are all not legit?
So based on this I decided to give it a shot with the PSU, if it works out great because some of these suppliers have awesome prices, would be nice to have someone from China to confirm this type of info though.
As I've said previously and others. I'd stay clear.
If they're sold out on Bitmains site, then why would a chinese reseller have full stock of them? Same goes with Pandaminers and Baikals etc...
Especially if there are no trade assurances. If you're in the bitcoin world and sending money to people without some kind of assurance, then you're in for a bad time. Believe me, I've been there.