> That's both not true and not the issue here.
> The Amazon.com Retail team probably won't be interested in buying it and selling it for $5 if he's selling it for $4 on his own site, but the marketplace/FBA side of things doesn't care at all… assuming it's actually a custom widget.
> You don't explicitly pay for the Prime badge. You need a Professional account to sign up for Seller Fulfilled Prime, but your eligibility is based on volume and performance.
Oh and I used to work at Amazon so these practices are not surprising.
 - https://www.inc.com/guadalupe-gonzalez/amazon-removes-price-...
As a consumer if I see a prime logo and it's not Fulfilled by Amazon I would feel scammed. Amazon Logistics is the only courier where I live that is reliable and on-time and I have little interest in buying anything on Amazon that is fulfilled a different way.