Just as with the 528 vs 540 car setup, the 10k delta really doesn't hold water. After adjusting for standard equipment in the 4.4 litre versions, (provided of course that you want these options), the delta is more lik 7,500 best I can tell. STILL ALOT OF money, but not 10k, to be fair. I did drive the two cars and the two trucks, and what I can say is that if you have the $$$ the V8 is an amazing motor, and I get over 26mpg on the highway in my 540i. I bought the 3.0 liter for my wife after alot of demo time, and while the torque just is not there, it does have ample power.