I'd custom build a PC, treat my room acoustically, buy extra peripherals (mics, **** like that), Yamaha H8s and the H8S. I'd purchase Kontakt, Spire, Nexus, ProFilter & Valhalla series and other VSTs if I need 2. Also a midi-keyboard. 61 keys sounds ideal but I'll take 88 for the lolz. Fancy chair, fancy table... Add a interface and I have my dream studio.
Should cost like 8K, 2k... Probably pump it into a business or market.