Mobo, CPU, RAM, and PSU would cost roughly $166 (most are obsolete, so you would have to use newer parts at roughly the same price) to build. Not sure what is an equivalent case for price comparison.
If it has three 2TB hard drives, I would say it might be a decent deal, even if all you reused was the case and HDDs. (PSU doesn't seem to be 80+ but might be)
Currently on NewEgg, Western Digital WD Green WD20EARX 2TB SATA 6.0Gb/s 3.5" Internal Hard Drive -Bare Drive is $110, so if you bought it, and gutted the case for new mobo/cpu/RAM/PSU, you would still save some money.