Yeah, I understand what you mean. That's a lot of money, no matter what kind of mod it is. For the people who have done just about all there is to be done, this might help, though. I don't know if there are any dead spots or big dropoff points in the GT-R's powerband, but the V-Cam really could help.
For example, 4th gen Maxima guys in the US got the variable intake manifold used on Maximas in the Middle East. The stock powerband dropped off drastically after about 6000rpm. With the 'MEVI' or 'Middle Eastern Variable Intake,' some owners reported gains of as much as 30hp on the top end, with a slight loss of low-end torque. Maybe this V-Cam system could have a similar effect.
I remember seeing a picture of the system a long time ago. I think it was installed on the 4G63 from an Evo. It looked something like the circular part on the cam cover of some of the newer RBs and SRs with VVT. It looked like there was a part there to adjust the cam/cam gear. Pretty vague description, right?