I did it doing all the labour and fabrication myself. Have about $3K spare to do it yourself. $5K-7K if you were to pay a workshop. Standard gaskets are expensive, about $400. Another $400 for lines, all the twin exhaust setup fits but the manifolds need to be cut and welded and match ported or an adaptor plate fabricated (part of this revision), fabricate a single AFM intake for the turbos, oil returns are a pig, the list goes on.
My goal was TT on a higher compression well built race engine, so I had a logical reason, and now done I'll stick with what I'm doing but not worth it just for bragging rights. I'm still contemplating a decent single and good manifold and selling the "kit" but still running the six throttles.
I am in the process of checking over the engine and fitting different turbos, new injectors, GTR throttles and intake and the adaptor for the exhaust manifolds so hope to be running again in about 4 weeks. Didn't get much time to try it as there was a problem with the injectors it seems. With a stuffed back I have been unable to do the pull down.