I think you'll be lucky if you can get USD 60 for it if you sell it on a second-hand site. That's about the price of a new 1 TB disk. But you can try USD 100.
I wanted to ask how much is my old PC worth. Tshis PC is very old. Run smoothly.
Cpu: Intel core (tm) 2
Graphics card: nVidia grforce 7600 gt
HDD: WD 1tb 7200 RPM
OS: Windows 7 ultimate