I may try to go the same route as Kanth. Since I have a similar cpu; (E8400@3.0 GHz) and I can overclock it, if that would be of any benefit.
I just scored 8 GB of DDR2 ram, now if I put a usb 3.0 card in, and upgrade my video card to one I would put in a new system if I build one anyways, I might be able to get into the VR world for right around a grand using a 1070 and rift. If I go with a card like the gtx960, and a Razer HDK2 I could do it for under $600, and that is very tempting.
Sik