Hi, you're interested in the digital picture frame?
Good evening.  Yes I am very interested in the picture frame.  Hope you are well tonight.  
I'm doing well, thank you. How are you?
Doing well.  I am willing to offer $18 for the picture frame, and will pay for any shipping.
Ah, I was looking for local buyers only I'm afraid. But maybe I could ship it. What payment method are you offering?
I will offer whatever payment method you prefer, and will include a prepaid shipping label.  
In that case, I will accept your offer of $18.
That is great.  Thank you very much.