09 saw the introduction of the F01 which is the current shape 7, so you will be looking at a massive price bump between 08 and 09.
The E65 is a supurb motor vehicle.
I have a 2006 750 which is in good condition, 200k and its yours, book is 300+
There are quite a couple of F01 750i's floating around in 09 year with 30 or 40k on the clock in the region of 550 to 600k.
The E65 saw the 4.9 V8 or the M62B49 motor, which in my mind is a marval of engineering,
The F01 however sees the N62 motor, and the 750 is a 4.4V8 with 2, count them, 2 turbo's on it.
The F01 is an absolute dream.
On the F01 750, most things are standard, heads up display, comfort seats, navigation, bla bla bla, so a 750 will give you a far broarder indication of pricing.