I love having a GTS non-turbo Skyline R33 for a number of reasons:
1) just coz it's a Skyline - it looks great, sounds great, and has plenty of power and acceleration to get me away from the lights quickly and legally (i.e. hitting the speed limit (or thereabouts ) quicker than most cars around you from a standing start is no problem). I still get plenty of stares wherever I drive, and all I've done to the car is add some 17" wheels to it.
All up, to get the car on the road, complied, registered, with new 17" wheels and high performance tyres, it has cost me about $15,500.
2) Non-turbos are cheaper to run (I still use the expensive Shell Optimax, but it lasts a lot longer than if I were running a turbo), and from what I read in reviews, if something is gonna go wrong with your Skyline, it'll be the turbo.
3) Insurance is a HEAP less (although some will still only offer third party fire & theft, not full comprehensive).
If you're looking to take your Skyline to the track, then a non-turbo is a waste of money, as it is fairly common knowledge that it would take a hell of a lot more money to get your non-turbo race-worthy than if you started with a GTSt.
Likewise, if you're looking to drag everyone off the lights, you are probably looking more for a turbo, but don't expect to keep your points/licence/car for very long anyway if you're street racing.
Well that's my rant anyway. Good luck antonahu!