Put the highest price you want to sell in BIN.
Enable OBO and put lowest price you want to sell.
Low ballers will send their offers , not messages and will get rejected automatically.
Seems like a good solution.
People in the northern hemisphere have forgotten how to bargain. I suppose that today the majority will only have some bargaining experience when buying a car or a house. Otherwise, all prices are fixed. In many countries in the south, you still have to bargain for almost all items.