Confusing UI market design

Within the in-game marketplace, when searching for an item I can see that it shows "negotiable price" yet there is no way to negotiate said price. You can't open chat when in the market window from what I can see and there is no button to actually negotiate the supposed negotiable price.
Do I have to write the players long name down on paper and then write it back into game chat after?
Seems like everything on the market is non-negotiable or there should be a button to message the player, or maybe clicking their name opens a chat or copies the name.

Quick workaround if you want to open chat while having market open, assign Chat another key in Settings.

Edit: You can also press the chat button