Well I was just thinkin bout the cost of my engine rebuild for RB30DET. It did not cost me anywhere near $7,000. Details...
Note that everything is pretty much at trade price & mates rates prices.
Block $100
RB30E Re-ring kit + bearings + Genuine nissan head gasket $440
Rebuild engine hone block machine crank pins to over size / clean deck block $330 (Mate)
Engine Mount $125
Clutch Plate $105
Exaust Manifold Studs $60
Mate at his own workshop to store car and do work after hours after work or weekend, he supplied everything needed from VCT setup to sending head away to be cleaned and reconditioned with new valve stems / competition fittings for sump for VVT oil drain & Turbo oil drain labour to remove engine dismantle and put all back together was only $2900.00 (+ many nights on the piss)
So totally cost me abouts $4000.
I think I got a great deal from my mate to do the RB30DET Conversion. He basically chucked in a free head rebuild and used new manifold gaskets.. I also put countless hours of work into it doing it with him.. The outcome was awesome but took us 4 months to do.