Hello are you interested in buying this?
you need to write here otherwise it won't be accepted we need to first agree on the amount
How about $150?
that's fine I will accept that. But still we need to write a bit more otherwise we will be returned back to the chat.
Okay, want me to pay in cash? Or wire transfer?
I'd prefer cash. How about you come get the item from me? 
Well, that's gonna be a problem I can't really go there but how about I pay for the shipping?
Okay that works for me. Just send me the address and I shall deliver it to you and let you know the amount for the shipping. 
1234 Looney Dr. Please let me know when you are able to ship it.
Sure I shall do it by the end of this week. Thank you for considering purchase with me.