I again would have to agree with what basically EVERYONE here has said mate, there is no conflicting arguments, which really is telling you something.
Firstly $3k insurance is a massive amount of money and if you have the money to buy a s2 R33 with that type of insurance money in 2-3 years time you'll have enough to buy yourself a R33 GTR or R34 GTT and most likely find the insurance will be cheaper.
These cars really are powerful machines and in the wet they are flate out dangerous even if you are being careful.
At 16 years old i just really dont think you should be purchasing a GTS-t without the proper experience. a GTS is definatly a better idea, they still look the same, they just dont have the added power that really is the main point most people are trying to make here.