It depends on what nation you are in. Assuming you are in the US, on eBay used 7600K chips are selling for ~$200. I don't think you'll get much more than that considering new they can be found for $225-$240 on Etailers (again, in the US).
Your motherboard is going for $150 new, so except maybe $125 for it. So combined you may get up to $325 or so, but more realistically like around $300. It all depends on what the buyer is willing to pay in lower cost than what he can buy the components new for.