Finding a reputable seller for CR-10S
I’ve bought two printers (CR-10S and Ender 2)from Tiny Machines in Houston Texas.  They unbox them from China and assemble them and make a test print.  You get a checklist of the tests performed.  They will also flash a bootloader and updated Marlin for $10.

Yeah, you’ll pay more but if you spend any time in printer forums you’ll hear lots of complaining about missing/broken parts or DOA units.

They also stock spare parts here in the US. 

Good luck to you!