Is this POTN-legal?

A For Sale ad in Classifieds which states: "I will take offers by PM" instead of simply listing a FS price.

I've always thought or assumed it was not, but upon recently (and finally) reading the rules a bit more carefully it sounds like maybe the only prohibition on a "best offer" type ad is that you can't have public offers.

Hoping a Mod can clarify.

Thanks.

That's correct. Prices are not required. Public negotiation is not allowed. Private negotiation is expected (via PM, email, or such other form of communication as you may choose to establish).