Amazon does co-mingle their own stock with marketplace stock, although exactly how often and for what items they do so is unknown. The board game industry has been hit hard by counterfeits (it's really not that hard to print a game), and there are many reports of people ordering games sold-and-shipped-by-amazon, and getting a counterfeit:
https://boardgamegeek.com/thread/1983918/warning-seems-be-lo...
https://boardgamegeek.com/thread/1923659/amazon-counterfeits
That's frustrating. It was the last remaining hope I had for Amazon purchases.
Yeah, it is. Thinking about it a little more, it possible that the counterfeits in this case are entering the flow at the distributor level, not at the amazon level, but we can't really tell from our perch at the consumer level.
I can't find anything to confirm or deny if this is still the case, but I haven't had any issues personally when sticking with products where Amazon is the seller of record. Although I have noticed the pricing and shipping time tend to be less competitive (I presumed because they don't access co-mingled inventory that's at a closer fulfillment center).