thats just depends on you i put alot of mods in my s15 because i am very competitive everytime i lose a race i would install a performance part etc i would just recommend to get one in good condition and dont be scared by the age but pay attention on how the owner kept it
my friend own a 34gtt which has so many performance part in his car but he never push the pedal (weirdo) and now he sold it 34000 which is a bargin consider all those goodies in it so i suggest there is cars thats well look after and has low price and just be paitient and shop around and jump at the opptunity if its a bargin