Why not bust buy a proper security camera system with local storage.
If you only need 400p video, a 4 camera wired system with 500GB of storage will generally cost about $200
and if you want closer to 1080p video, then $700 gets you a 4 camera 1080p system with 2+ TB
While you get a higher upfront cost with a dedicated system, you save money in the long run as in a little over 1 year, the local 4 camera system that will do 1080p and also offer more than 30 days of recording
and best of all, no cloud requirement.
dropcam becomes useless if you do not pay for the service, or if they go out of business since the cameras cannot be used locally.