??? If you want a camera then you need power, they dont run off magic!
Battery ones are pants.
Basically if you get yourself a decent camera, you will be annoyed if you dont spend your budget on this.
You then need to either plug it in, or you can get cable that sends both power and video to the camera. So at one end it plugs into your camera, the other end video into your DVR and power into a distribution box.
So my mate used to run a CCTV company and he swears by cops cctv equipment:
Inspire Silver 4 Channel DVR,
http://www.onestopcctv.co.uk/inspire_silverInspire day/night mini vandal dome 520TVL,
http://www.onestopcctv.co.uk/product/OS-315D-H?form_42.replyids=720 metre video-audio-power cable
http://www.onestopcctv.co.uk/product/OS-W001A12v 2A 4 x 500mA boxed PSU
http://www.onestopcctv.co.uk/product/OS-PR207You would then be able to see your camera on your smart phone anywhere in the world providing you have a internet connection, it will be recorded and its quality kit.
The prices on that site are massively inflated, id contact them and offer them 1/2 that and work up.