I think it's one of those cars which is relatively speaking so rare that someone could easily pay that kind of money. But I strongly suspect it's now got to the stage where any prospective buyer should be thinking in terms of a total underbody strip and probably a full respray too.
I'd be surprised if it's running a genuine 450bhp. The Evo 8 engine in it at the time I sold it was from an FQ400, so is forged, but it would have a lot of miles on it by now. And the gearbox, transfer box and RS diff may very well be the original items and therefore have at least 100k miles done on them.