I am interested in the Infinity
Sounds good, let's negotiate.  Everything is fully working on this car and the sticker price is $15,000.00
I would like to ofeer 8500
Unfortunately that is lower than I can work with.  This has been a lightly used car and everything is in proper working order.  You'll have to do better than that.
Last offer of 9000 or I walk
I can do $9800, but if $9000 is your low, then I don't think we can make a deal.