I would suggest to return it back regardless of how much it is.. I lost my wallet once with large amount of $$$ few months ago. Nope, No one returned it but I just accept it and kept my cool about it. Of course, Its my fault that it fell out of my car. I needed that money for certain bills but oh well. IT would be nice to have someone to return the lost wallet or purse back to the owner no matter what. When I see my children find something value, I ask them to find the owners first before keep it. I always tell them that if you do a good deed and you will have a good deed coming back to you. If you steal it and someone will steal something from them.. I just hope they will take it in their heart...