there might be $300 of used parts there. and that's being kind. the key being used, and you don't know how hard. HD's don't last forever.... are they 3-4 years old now ? the video card is a long gone joke and near useless for anything after COD2. Don't know what all that ram was for but it's pretty much overkill and the processor still has use but it's still old. PS...... older they get...... I wouldn't buy it.
If it comes with the operating disc ( a real disc ) offer $200. or walk away. No operating system don't touch it.
Yeah, wouldnt bother with that system. The CPU is about 3rs old and the graphics card quite a bit older.
To put that in context, a modern Core i3 (3220) will outperform that old i7. http://www.anandtech.com/bench/Product/46?vs=677
The card is so old that there isnt even the option to compare to modern cards, but even budget cards from last gen will outperform it by quite a bit.
Plus the issues raised about how used it is, HDD's and PSU's dont age well. The only thing I would consider salvaging would be the RAM and case (depending on model and condition), but you would have to get the whole thing for $100 for it to be worth it.