it can be done cheap despire what peopla say
i did my CA18DE+t conversion for $1500 with most of the stuff not being stock and i bought everything seperately so it could have been done cheaper
and i probably already had $500 worth of stuff in the car that i used for the conversion, so $2000 all up for engine running in the car
my first r31 diff cost me $200 by the time it was bolted into my 1200
tailshaft was $80
front suspention and brakes would have been about $500, $700 by the time they were coilovers...thats with r32/33 brakes

mind you ive since spent about $2500 on a forged rebuild for the CA, $300 larger turbo, $400 for rebuilt r31 gearbox. and will spend plenty more on it when i actually start making more power from the engine