i got an rb 30 motor im gonna turbo currently for my vn and been pricing things up, been looking on ebay for parts.
roughly
turbo manifold $3-500
turbo standard $500ish thats for a second hand turbo, try to find a good 1 with a free play in the shaft.
upgraded turbo $1000 (depending on what sort)
exhaust to cat im not too sure yet i'll be thinking round the 600 buck mark.
you will also need to change your computer mapping which shouldnt be too much i dont think but i'd leave bout 2-300 bucks for that or go onto ebay to look for a turbo 1.
and im not too sure how the standard plenum and injectors will go, so look into then but they aren't a neccesity.
injectors $2-300, plenum $400
that would be a basic kinda conversion price.