That's cool and it's your decision, for yourself only. You don't get to make that decision for me or anyone else. Lots of times I've had to stop looking for a disc because of darkness or some kind of external time limitation, and come back the next day to look for it.
As for the OP, also I understand there is a possibility that the 2-disc guy may have gotten it through completely legitimate means, so I'd offer him $5 or a trade.
Your hard to find disc is going to be found by someone in the darkness the same night you lost it nearing darkness? Cool story.