10k/10k is the best build...
It is marginally better, that's true. It is also 2.5kk more expensive however. On average it should take 8-10 top tier seasons after completion to get ahead with it. And possibly roughly the same amount of time to compensate for lost profits while building it.
So in the very long term - yeah, this is most economically viable build. In short to mid term - not really.