i've bought quite a bit of stuff from amazon, and from their third party sellers. Only had a problem with a few items, one a USB 3.1 Type C external enclosure for a mSata draive. DIdn't work no matter what prayers i said over it, it was from a 3rd party vendor, i informed amazon, and they sent me a return label to ship it back to the vendor (located in Illinois.
Personally, i don't think there's any problem with 3rd party sellers on amazon, in terms of getting scammed. But in terms of warranty service a month or more after receiving the product, i'd be careful - check their feedback. The Asrock Taichi Z390 mobo i bought, came from a 3rd party vendor and when it fried itself 2 weeks after arriving, he referred me to Asrock