Well..
1500-2000 dollars for the engine if you get an import, what are you doing about brakes and gearbox with this?
No matter what you turbo, whether it’s the current engine in your car, or whether you get that engine rebuilt or build an rb30et or purchase an import then brakes and gearbox will have to be considered, the n/a auto's will not hold, and the n/a manuals will hold for a while. But you will have to look at upgrading eventually.
Now, my opinion on the rb20det isn't really that high, I've driven a couple before but the fastest one I'd driven still 'felt' slow.
The 2litre simply doesn't provide enough torque for my likings and is as gutless as an excel until boost hits. In most cases boost is coming on early. But it still isn't enough.
Lets just say that I had a run in with my mates r32 gts-t. Larger turbo, rebuilt with a larger fuel supply, front mount intercooler, manual, brass button clutch and 15psi with a 3" exhaust vs my converted vlt manual, 7 psi- stock cat and 2.5" exhaust I got a lead, he was slowing pulling away at very high top end. 170km/h plus.
Driving his car was just like driving an excel with some plugs missing until boost hit, whereas mine was just like driving an n/a car - and then boost hit.
To convert the n/a you have now - you could probably do it for 1000 dollars if you get your bargains. 1500 easy. Like I said that’s not including gearbox, brakes - driveline etc.
To do it properly with the engine rebuilt, your looking at that figure plus the engine build, 1500-2500 + 1-1.5 thousand.
Depends on your money, in most cases its often cheaper to buy a vlt and do it up, unless you really really want to keep your car because of good paint etc