Just a thought regarding the BBB. While I agree they are pretty worthless when it comes to resolving complaints, I think I would still post complaints with them simply because many people look to them for the track record of a company. If you post your complaint with them at least it now appears to those folks and can serve as a warning flag that more diligence may be needed on the buyers part.
Dave
900x600 80watt EFR Tube laser from Liaocheng Ray Fine Tech LTD. Also a 900x600 2.5kw spindle CNC from Ray Fine. And my main tool, a well used and loved Jet 1642 Woodlathe with an outboard toolrest that helps me work from 36 inch diameters down to reallllllly tiny stuff.