hello, Are you interested in buying my truck today?
Yes I am interested.  I think 8700 is a little beyond my price range.  Can we negotiate a bit?
Yes, I think we could make that happen
Okay.  Would you take 7700?
It is a great vehicle.  Cost me 38,000 originally and still works great.  It has a clean title and runs like new.  AC, heater all work great.  Could you do $8450?
Hmmm.  Well, I think that's still a little high.  It's got quite a few miles on it for a vehicle only 6 years old.  
It was used for landscaping, so it has some mileage on it; however, for a truck only 6 years old, it is a 4 wheel drive, well maintained, runs good, everything works perfect.  How about 8200?
I did a search on KBB.com for used vehicle value and it came back with 7830.  That's my limit, I'd say.