I'm with Sstupid here

I love the y34s, and the power is honestly not much different than the later generations.
One of the downsides of getting one is the parts availability. Be it mechanical components or even body panels.
2nd downside is the technology. The one you're looking at doesn't seem to have navigation nor does it have the climate controlled seats(if you're comfort feature-oriented like I am). You can get surround sound, dvd, cooled seats, backup camera, lane departure warning, intelligent cruise, spacious seating etc...If you jump up just a couple of years.
Personally, I would buy an 04 m45, yes, but not at that price. I've seen 06+ M45s with around the same mileage going for around the same price.
And like someone else said, blue book isn't exactly the bible of car-pricing. Rare cars like the m45, usually sell for more than blue book. I paid more than book value when I bought mine and I don't regret it.
That's my piece of advice on whether you should buy it. But if you're definitely going to get it, then it will give you 100,000 miles with little issue. I can type up the things to look out for at a later time.