My workplace operates over 100 q-see cameras from Costco. They are a very good system for the ultra low price point compared to other DVR systems.

Highly recommend.

We were actually considering the Costco cameras, nice to know they are worth the investment. How is the quality of the recordings, its one thing to have a system, its another to be able to use the footage as evidence. Any concerns with quality?

There are different generations of cameras and kits available from QSee. We use some of the older ones, and the picture quality isn't the best (still good to id a person), but QSee does offer better cameras. The important piece of the system is really the DVR, and being able to easily use it. Cameras can always be replaced, added, or upgraded. We use high quality panasonic cctv cams for entrances, then the QSee cameras for movement capture.

I had a system installed in our business from the Surveillance Shop in Calgary.
High definition video, and it can be pricey.
It was a few years ago, maybe they have more affordable setups available now.

http://www.survshop.com/

I bought 2megapixel ip cameras online. They're not cheap but the quality is amazing and the night vision is perfect.