You're right, there are fewer of these every year, but in saying that, how much are you willing to pay to have something that you really want? Are you prepared to pay for the troubles and associated costs that a nostalgic vehicle like this brings?
Buy this and you'll probably wonder why you did when the repair bills start to come in. But if you really want it, buy it. The answer to the question lies with you alone. Many people will call you mad, and the rest will say that it's a cool car because of the rarity. Who knows, in a the years to come they may be up there with the KPGC10.
Personally I wouldn't do it, but as I said, it depends on how much YOU want it.
Good luck with it though man.