Depends on the trash. A co-worker and I would regularly grab prototype machines out of our dumpster. Thousands of dollars of quality electromechanical hardware (motors, precision linear slides, pneumatic cylinders, mini-compressors & solenoid valves, etc.) and big sheets of 6061 aluminum for the taking. Company had to throw it out and tell us not to take back out in order to take the write off.

At one point we upgraded to having an intern standing in the dumpster throwing stuff out to us as we directed him.