How exactly would it be 2x better than RenaultSports R3 manifold, power, build? What are you defining against?
I paid £800 for my R3 mani built by Aros. But it's cost a fair bit to have installed because R3 manifolds have no flexi's, therefore we had to covert the front joint a sprung system like a 182 which allows movement. Also runs like a dog tbh and needs mapping (tomorrow), whole cost just shy of £1800 (not including system/backbox either!) so never worth it!!!
The only manifold that stands a chance of being a real sucsess is if someone does a halfway house between the R3 and Toyo/KTR.