Hi, are you interested in my headphones?
Very. Is there a reason you are getting rid of them?
They're just more headphone than I need! I bought them to cancel noise on a flight, but usually I just use earbuds.
Are you able to lower the price?
I don't want to go too low, but I have some flexibility. What are you willing to offer?
I'd like to offer $100 
How about $125? They're in like new condition, and that's still a lot lower than buying them new.
I could do that. Can I get them today?