Value in RFID chips?

There are many different kind of RFID tags made out of a variety of different materials. Usually the materials chosen are cheap as humanly possible, and they are always trying to find ways to make them cheaper. The passive tags are a lot cheaper then the active ones. Also, I think that some types of passive low frequency tags have copper coils. If the tags work you might want to see if they have resell value. The cheap ink ones like the ones they often stick on produces stores now days are only worth a few cents new, but some of the other types are worth more I think.