But what if it had already cost $10k in resources to recruit him and get him this far? What if it costs $10k to find the next person who will accept $100k? Then it's a wash, and all you've done is lost time.
It's only a wash if your only gauge is money. If you hire him, you've potentially sacrificed moral. Sure, it isn't immediately meassurable in dollars, but it is still an important price to pay.
