IF computer parts are like many other technical items i have seen many are grade b (for want of a description)
Like the reason a Euro Nokia (i.e one made in Finland is worth far more when reselling than a made in china equivalent)
Many pcs i have seen in phill for sale even in large city stores when i first started browsing for the wife three-four years ago were recons or im sure not grade A.
I know from first hand experience not with pcs but other electrical and I.T equipment sadly this is done by several very very large companies.
Also many spare parts (not all of course) are counterfiet or made to a standard would never pass H and S regs in the west.
I have personally vetoed many items that were going to be bought and have upgraded several power supplies that the family use as when i check them out they dont meet standards i would expect for customers of mine so why would i allow it with my family?
Just as a Doctor would do on health reasons.
We did used to buy battries for items like mobiles in phill but now unless i can verify they are geniune either made by the manufacuter or well known companies like ora for example who make cheaper versions.
Heres some info on ghost disks
http://en.wikipedia.org/wiki/Ghost_(software)