I don't get you, guys, "you can build a good PC for 2000$", that doesn't answer his question.
Anyway, I would have spend on a SSD raid. A Hardware RAID PCIe with cache (Adaptec RAID 5805 700$), And a few SSD (1TB ssd, something like 4x50$), That's 2500$ for a extreme disk performance ! http://www.tomshardware.com/reviews/ssd-6gb-raid,2388-5.html They achieve 3.4 GB/S with 116 disks. Because you don't want to wait to play 4K, right ? ;p