Hello there, are you interested in my John Deer Pedal Tractor?
Yes I am very interested in the tractor!
I am asking $350 for the tractor, it's in mint condition so that's a good deal. 
What is the retail price of the tractor brand new?
It is selling for $500 new, the one I'm selling is still new
It's my sons birthday in a few days and I think I want to get this for him. How soon would I be able to get it?
I can do it today or anytime this week, I'm off for the week
Would you be willing to go any lower for the tractor or is that your final price on it?
Well..that's already a really good price. What are you offering? 
Would you take 300?
How about we meet in the middle, I'll do it for $325
That sounds great. It's a deal.  I will go ahead and submit the offer