I do a lot of CCTV work at work,and we have completely switched away from tape recording, and have gone to a PC based digital recording system. Unfortunately, a price of $800-$1000 a camera for pc-based systems is about the going price. The system we use is made by Salient Systems and is a super system!
The real advantage of digital systems is their ability to only record true motion events. You set up a grid on the screen, and define the areas of the grid that you wish to watch for movement, and the system only records when the pixels in that area of the picture are changing. You have not lived until you have watched hours of videotape looking for when an event happened. With digital, you only see activity, and not hours of no movement. The system can be hung on a LAN or can be connected to a internet connection, and can alert a remote site and transmit the images to that computer. It is really nice to be able to burn a CD and hand it to the police when we have an incident!
Time-lapse recorders are a dying breed and can probably be obtained on Ebay for a small fraction of what they originally cost. Brand new, top quality VGA cameras are pretty cheap now days, but I would not buy a camera with less than a 1/3" CCD in order to get quality resolution.
Another issue is the light level. Color cameras do not work as well in low light levels as black and white cameras do. Most of our exterior cameras switch automatically from color to B&W when darkness falls. This function adds a lot to the price of a camera, so you might be well off with a B&W camera if part of it's time is spent recording in the dark or near dark. You can even put an infrared illuminator in that will be invisible to the human eye, but will allow recording in total darkness. Such illuminators are very cheap and can be obtained almost anywhere.
Regards, John McGraw