I'm sure there's plenty of Porsche owners who would look at the frankly stupid amounts of money some of us spend on our cars and say the same thing. Why not just buy an x, y, or z.
Had he bought an R32, he would own an R32, like countless other people. But he doesn't, he owns the only 4wd, RB30 S13, and isn't that the core of why people modify cars?
Also, how do you know it will drive like an R32? That's not something anyone can know without having driven it, or heard from the man himself. It's a completely different chassis, body, weight distribution etc. It's not like putting a different plastic shell over an RC car