As with a computer, the first information we need to give a decent answer is "What do you want to do with it". Examples are check on kids in home, check on pets in home, nanny cam, or outside security for prowlers. Do you want video only or video and audio? Some states require written consent (really!) for audio recording.
That said, any security cameras will need to be effective enough at entrance and exit to positively ID people, actions and vehicles for police purposes. In 2015 720P is a minimum and 1080P and up are desirable.
Costco has a 8 Camera outside/inside day/night video only 1080P stand alone system for $500.
http://www.costco.com/.product.1002...geHorizontalTop|PersonalizedClickCPInCategory My boy has this system and is pleased. We changed the fan (quieter and $6 on Amazon) and several Lenses ($8 each on Amazon) to get the zoom for 40 to 80 feet. You can see this system in operation at my local Costco, so check yours if you are interested . Here is a video of the 720P/16 version with the great $550 addon zoom camera.
https://www.youtube.com/watch?v=e9XFmIVfvnQ
We let the footage collect on the 2TB hard drive if it is ever needed. We have not tried viewing over the internet. The price is about double for an IP system with similar video.
Jim