If someone has an ad listed with obo, I’ve always felt it was more respectful to just ask what their best and final price would be; versus throwing out a price that might be considered low to them. If someone responds with their best price , and it’s higher than I am willing to pay, I can say thanks and move on.

I think it depends on the person and situation. My example would be if there is a pin listed with an obo and it’s on the other side of the country, I know it’s going to cost me another 4-500 to get it. I realize it’s not the sellers problem at all, but if I ask the seller what’s the lowest they are willing to accept, I know right away if still makes sense for me to buy it. I think if everyone is polite it saves time. Once the seller tells me their number , I personally wouldn’t try to go any lower.. I’d say lets do it or thank you for your time. But I can understand what others have said as well, I guess it just depends how the seller interrupts it.