Well I will add up my levin build just for you
Cage Steel - $250
reenforcment plates - $10
paint - $50
harnesses + padding - $330
underbody protection - free (I did welding and forming, materials from scrap)
Probably sunk $2500 into the engine, cant be bothered going into details (turbo 4age, all fabrication done by my dad and I)
Over $1000 into the suspension, lots more still planed
$1000 for car purchase ae92 levin facelift
$300 for club membership, homologation, authority card, licence and log book
$500 for exhaust system
I havent done enough events to see how reliable it is, it seems to be holding up fine because im not making stupid amounts of power.
Thats almost $6000 all up, thats probably what I would expect if you were to do all the work youself and had access to the right tools.
I prefer grass roots stuff, build your car, race it, have fun
Oh also you'll need a helmet and overalls. I use work overalls (they are 100% cotton)
Im very proud of what my dad and I have built, its been about a year in the making but in the end im very happy with it. If your good with a grinder and welder go hard!
Oh the cheap end of the scale you could buy a corolla and
- strip it out
- half cage
- harness
- decent shock absorbers
leave it as that, just make sure you get a 4age powered one
it'll be hella fun on gravel/dirt and wont cost you the earth. You'll be able to do most clubsport
Anyway some useful articles
http://www.motorsport.org.nz/Regs/regulations.htm#RegsClubSport