Greekos, your right there, find a good one..............but I'd have to say that Skylines are the bargain of the century at the moment, you get a truely awesome platform with an aftermarket support base like no other vehicle, performance to match 80-90% of other domestic cars, heaps of potential to increase that percentage, and all for sub $20K. Try buying a supercharged or V8 SS commodore with climate control, electric windows and ABS etc for that price and in the same condition.
The only downside is insurance, who'd want to insure a $15K vehicle for $3K per year, doesn't make sense. In modern terms, $15K is nothing.
Also, as an example if I had to replace my Skyline with something comparable, I'd be up for $80K+, and I'd rather spend my $$$ on other things.
So if you buy, look about and see how much car you get for the $$$, its a no brainer I reckon.