I am always skeptical of pretty much anything that comes directly from China. They seem to have decent prices on occasion but I’m wondering how you go about figuring out if they are just foreign scammers trying to make an easy buck.
buy something cheap that if you dont get it at least you wont feel so bad. Example would be buy a $400 item and see how that goes. Then step up to a $2500 item and see how that goes. If you really want a 15K item then I would not even use a site like you have posted. They appear to be just some place that is clearing out the old miners that can no longer be used in China. They only created the website Oct 9th 2021 via Alibaba using https://sanmimining.com/