You'll see that in the FTC's example, you need to click to see more buying details and that at the time of this comment the lowest price is $14.28 with free shipping (on October 12th for my location).
In the other example, the "buy box" highlights the best offer of $9.99 with free shipping (on October 5th for my location).
That first example is eye-opening for me. I always thought that when Amazon doesn't show a buy button on the product page, it's because that product is not currently available to be shipped from Amazon.
That's one possibility! But Amazon also hides the buy box when the only offers are not what Amazon considers "competitive" because it hurts their brand if consumers see shitty deals.
In this example, the pens with the buy box are 50% cheaper and have much faster shipping.
They're not the same pens though (extra fine v. ultra fine).
I can understand why the FTC is concerned. This has the potential to be worse for competition than MFN agreements, because it forces any supplier whose products might end up on Amazon to police its entire distribution network for minimum pricing.* It also forces suppliers to crack down on (legal, authentic) grey market imports, even if those are never sold on Amazon, or risk losing the ability to effectively sell on Amazon.
* Moreover, that minimum pricing has to be sufficiently high to account for Amazon's cost structure, even if other competing vendors are more efficient.
I was offering the comparison because those two pens should be priced within a few cents of eachother (the difference is the tip width and ironically "extra fine" is more expensive). If the products were the same then there would only be one product page and the $9.99 offer would be the highlighted deal.
The fact that one product has the buy box at $9.99 and 1-day shipping and the other product does not have the buy box at $14.28 and 8-day shipping lets us infer that $14.28 is not a competitive price for these pens and there may be a cheaper price elsewhere (likely closer to $9.99).
You seem to be thinking that manufacturing costs alone dictate the product cost. Demand and volume in circulation are also part of what determines costs, though. That is, your first assertion that they should be within cents of each other is clearly wrong.
It doesn't let us infer that there is a cheaper cost somewhere, it lets us infer that Amazon has a low confidence that someone will buy it. That or they have such a low inventory of it that they are not confident showing it on the buy box without more engagement from the users.
To be clear, I'm ok with the idea that this is getting investigated. I have low confidence of finding smoking gun reasons to punish sellers on this. I am far more confident that Amazon is optimizing to convert sales.
Actually, in this case I am cheating because I already know that this SKU is offered for a lower price with faster shipping from Walmart. I suspect that listing is what triggered the loss of the buy box.
But that is a non-sequitur. Literally, in that that doesn't necessarily follow. We literally don't know why the buy box doesn't have it here and I could guess at a few other reasons. Most likely, I'd guess that the cheapest option not being Prime factors in to it more so than external offers being cheaper.
You're right, shipping speed likely also factors into it in addition to cost (that's why I also mentioned the shipping speed). If Amazon can't deliver within its 2-day Prime guarantee it is less likely to promote the offer.
Of course, without access to Amazon's systems I can't say for sure why any individual listing is or is not promoted. I'm just making an educated guess based on what the FTC put in its complaint.
As a consumer I definitely avoid products with no buy box. I thought it was only related to Amazon fulfillment (which in turn I use as a proxy for being likely to receive the product on time and undamaged)
That's funny. I _only_ buy things from Amazon that are not shipped by Amazon.
Their logistics are utter garbage for me - part of it is an urban setting with nowhere to leave things, part of it is that they don't give a shit, and leave things.
https://www.amazon.com/Pilot-Retractable-Rollerball-Extra-Re...
Compare it to this listing for a very similar product:
https://www.amazon.com/Pilot-Retractable-Rollerball-Ultra-0-...
You'll see that in the FTC's example, you need to click to see more buying details and that at the time of this comment the lowest price is $14.28 with free shipping (on October 12th for my location).
In the other example, the "buy box" highlights the best offer of $9.99 with free shipping (on October 5th for my location).