I'm not sure if the argument holds up about haggling as the price is on the ticket, so a dealer is hardly able to double it on the spot just because someone is looking at a coin.
Displaying the coins is the hardest job because to accommodate coin, details and price in a manner that makes all the info distinctly visible takes up an unrealistic amount of space, so there has to be some form of compromise. The most obvious thing to hide is the price because people aren't looking to spend a certain amout irrespective of the coin, but even so, the problem persists even just displaying the date info and the coin. People can't read the date in the exergue very easily, so I have settled for showing the date and working on the premise that the collector is able to identify the denomination from the flan size. Even so, given the quick scan that many make over a table before moving on in a very short space of time still means that engaging is the easiest way to draw their attention to what they are looking for, which is why the unresponsive nature of customers is so frustrating.
However weird and wonderful the collecting habits of individuals, dealers don't care. We are all trying to sell coins, not find suitable candidates for the funny farm.