I guess its the vendors watch to sell and they can sell it however they like.

However, while I would buy from a private seller on this basis, I wouldn't buy from a dealer or store- I've been messed around (as many have) and you wonder whether the item is really for sale or only available for a silly price. I see no reason to be shy- if its a rare watch and you want a high price, just ask. If you want to auction it, then fair enough, there are plenty of platforms to do that.

In the past- and this goes back years- I've asked for a price from a dealer and been told to make an offer. I made an offer and agreed a price. When it came time to pay the price had changed. That was the end of it for me.

Now, when a private seller becomes a dealer is a harder question.