I say every man and his dog drives one becuase there are so many of them around now... Hard for me to say for Sydney but there are alot around Brisbane.
Its perfectly reasonable that you wouldnt want to pay $30+k for an S15.. each to there own, I had the moeny so i bought it, and as i said i much prefer it over my R32 and any R33 i've driven or been in. Don't forget insurance is cheaper, running costs over time are cheaper due to the skyline being an older car mroe and more things tend to break.
I dont see how $30k is double the price? You can get 33's for $25k and you can get S15's for $28 at the lowest. Looking at both ends of the scale you have to ask yourself is it worth paying $3 - $5k for a better/newer car?
The reason i'm selling is because i have purchased a block of land and to build the house i need to sell the car.