Good find, as one of the posts said on the site, it happens more than you think.
Ever watch antiques roadshow, guy found 16th century watercolors worth millions at a dump.
I work at a University where the students have more money than sense. In May around graduation you can find all kinds of stuff ranging from mac computers to stereos and TV's laying by the road or in the dumpsters by the dorms. it is hilarious to see some of us faculty diving and helping each other get stuff out. and the faculty that you would least expect to be digging in the trash. "Teamwork"