Yes, well obviously it is not a E92, sure.
But he is wanting something bigger, due to an expanding family. Doesn't necessarily want something sporty, but the V8 Disco would have plenty power. He's only doing 7-8 k per year so the petrol costs wont be too crippling. They are nice to drive and comfortable, so the only issue there really is reliability. But any decent car at that budget could have issues.
So it's not as HUGE a leap as you guys are making it out to be.
As for the S600 comment, that is absurd. Should have specced him an MX5, equally absurd. He didn't ask for some weapon spec saloon, or a two seater "sports" car.
A Discovery makes for a reasonably sensible family motor with plenty of toys, and a HUGE boot. Sure, going for a V8 one may be the lunatic point there, but the diesel one would be fast enough, and probably not all that much more on fuel than the 325i. Reliability may be an issue, but I had a grand total of 1 problem with my V8 P38 during my ownership, and that was a window regulator that cost £40. Hardly in keeping with its reputation.