I think the technical term for it is "Price Fixing".

It's part of the ongoing investigation with the FTC. But meanwhile, Amazon will come up with meaningless prices, and insist that you list lower than that price. Most common is the "list price" of a book that has been out of print for 50 years, so you should be selling it at the (non-inflation adjusted) price that it sold for in 1970. Other times, it can be a "competing offer", perhaps a copy on eBay advertised as "great condition, other than missing cover and first 20 pages" (Yes, that was one that I actually tracked down; I was to drop my "Like New" copy to match that). The irony in many cases is my price might be half the price of the copy in the BB on other Amazon sites (in countries where price-fixing is illegal and enforced).

There are only two things I know of to do. First is to list the book in a Collectible condition; but note that there must be something collectible about it, and that fact stated in the description. Thankfully, Amazon accepts "Out of print" as a legitimate reason to call it collectible (even though any good bookseller would say that's not enough). The upside to "Collectible" is that the price bots don't usually flag it; the downside is that you won't get the BB, and won't always show up in searches. Still, I've sold quite a few books for far more than Amazon suggested by selling as Collectible.

The other option, of course, is to list them elsewhere. Apparently Amazon would prefer that a book not be available at all on Amazon, rather than being priced competitively with other sources.

Hopefully, the FTC will put a stop to this.