Just re-read my Post. It should read "about £5K less..."
David sold cars for a few years in his formative years before he got a real job!
The X5 in question was probably an ex company purchase so they didn't haggle on the trade in they got or it was possibly on a Lease deal anyway.
As David said "I always knew what I was taking in and selling on. No way would I have let a gem like that slip through my fingers!"
That Dealership was a Volvo outlet so was much more interested in the New Cars going out to meet Targets than the trade ins.
Their loss, his gain.