I think Torque Test Channel or one of the popular YouTube channels recently found that many spark plugs they ordered from Amazon were potentially fakes. eBay was just as bad.
Gump, that shipping from 4 warehouses thing is not uncommon. I go elsewhere if that is my only option on RA... but 99% of the time I can come up with an order on there with reasonable shipping and not that BS.
I know others have had issues with RA, and I know I'm probably their biggest fan on TRS, just know I'm speaking from experience. I have probably 100+ magnets on the side of my tool box to prove it. I have had no worse luck with RA than any other vendor. Sometimes you have to shop around though and I'm not afraid to do that - eBay, Amazon, Partsgeek, smaller places (Quadratec, LMC, Speedway,) etc...all great alternatives.