You could build the same PC, if not better, for around $2k.
The SSD and the PSU together net about $800, which mostly is wasted money.
Sound card is also not needed because MOBO has integrated ones already.
The graphics cards are top of the line obsolete tech.
The monitors and printer are about $260 each.
I would say if he sold it for $2500 then it would be a deal, but $4000 is not worth it.
Just save yourself some money and start a thread for a full computer system w/monitors, printer, kb&m, OS, desk, chair and lamp for $4000.