How protect large amount of cheap properties

[admin]

Your sign cost only $25, almost no anti-theft mechanism cost less than that in particularly you want it to keep track within a wide area.

Sometimes we want to put something in public area and in large quantity. Though it is not expensive, it is ideal not to be stolen.

Is there some hardware can be used to track this item?

GPS is no possible.

RFID chip is low cost, however, it requires a sensor cost much and this technology is for proximity detection only. Is there public RFID sensor around?

One more option is using wireless alarm system, a vibration sensor cost much less could be attached to each item, but you still need a alarm panel that covers an area of about 100 x 100m ideal. This setup will not locate your item if moved, only know it's moved.

Therefore, I would guess a viable solution for you is to
1) increase the cost of item being stolen, each fixed with strong screw.
2) reduce the cost of item replacement
3) better manual monitor procedure to identify item being stolen and replaced immediately.

Hope this help.