Be careful about making any sort of "agreement" with the other guy for payment. Once you do that the police may consider it a civil matter and you won't have the option of having the police investigate the incident as a theft.

I'd call the police and report everything right away. There's no excuse for the guy taking your things. Once it's recovered, depending on what the guy who took it says (ie: "Oh, sorry. It was just a mistake.") you can decide then on whether or not to pursue a criminal complaint.