True, but that's useless to the customer, who has no idea of whether commingling happens or not. The other day I found myself needing printer toner. Amazon has

True, but that's useless to the customer, who has no idea of whether commingling happens or not. The other day I found myself needing printer toner. Amazon has a much better price, even when they sell it themselves, than local stores. But then I see that along with the "sold and shipped by amazon", which is still quite cheap, there are dozens of even cheaper options, some of which are fulfilled by Amazon anyway. So how do I know I am buying a new, original cartridge, an honest, quality refurb, or something that might print badly, or even damage my printer? Even the sold by Amazon merchandise, which I'd hope is original, could be comingled with a refilled knock off that might be indistinguishable out of the box, but will be very different in operations. For something like this, as a consumer, I absolutely need to know the provenance of what I am purchasing, and the chance that there is commingling means I cannot buy something like this from Amazon, as I won't even be able to tell for a while.