Power cables and power conditioning seem the next focus components. While I struggle, as I'm sure many do paying premium for a chunk of wire, it seems that when done well, that chunk of wire is now an influential component in the chain allowing everything to shine.
I've slowly been upgrading all PCs with Furutech 4.1 with appropriate connectors and it has been nothing short of revelatory moving the needle of performance for the whole system. I can liken it to completely refining a fuel injection system which in turn allows everything to work better producing better performance.
I've capped my insanity with the Furutech and do not see myself moving beyond that. While certainly real capital, not hide the women and children capital like some products left unnamed.