Looking for a device (not a 'system') that your average lowly Guard can plug into wall (or battery power option a major plus) and connect to WWW to download to home PC, and/or access via smart-phone.

Assume there is local WiFi access, or be able to use dedicated Smart Phone hot-spot for WiFi and maybe just upload a pic every few seconds.

Under $100, since might need to be left in place where it might get stolen.