Your pc is probably worth much less than you think.
Few will want to buy a "K" cpu and a non-overclockable motherboard.
Search for your pc or similar on ebay in used condition.
Then filter on completed auctions and you will see actual selling prices in green.
Unless you can find a private buyer, you can likely do better by separating out the parts and selling them individually.
If your os is oem, bundle it with the motherboard.