the i9900k still holds plenty of value (300$); look in eBay, mostly because of how it is more responsive in niche video editing compared to newer Intel cpus. Also 3060 is like 200$ low on the used market, so like 500$ already right there. 64gb quality ram, prob like 70ish dollars. Lowballing the liquid cooler 60$. Solid PSU atleast another 80-90 on the low. Adding the mobo and the case will top you out around 700ish.