I have been playing with trail and other remote cameras including a few security cameras. Cctv systems are notoriously pricey and often unaffordable and some of the cheaper systems are very unreliable suffering the problem of long delays befor activating the camera.
There is also an impressive range of fake cctv cameras in the shape of domes and bullet cameras which are considerably cheaper, but often don't look the part at all. Better than these are a slightly more expensive range of fake cameras complete with the low glow of fake infrared arrays, randomly flashing communications LEDs and cabling. They are effective decoys especially where what is needed is a deterent.
Trail cams are a different technology entirely the lowest cost of these self contained motion sensing automatic cameras able to operate in daylight and total darkness (zero lux) is around £80-100. Some are fitted with a flash, others with infrared illuninators. Some models save to a removable SD card, others are 3g enabled fitted with a SIM card and able to email or sms the image to your specified address. 3g enabled trail cameras too are not cheap costs can exceed £200-300. Trail cams do however produce some very good and unexpected results.
Remote photography, especially when what you are trying to photograph is illusive is still reliant on good tracking, observation and understanding the habit patterns of the animal you want to photograph and even then the results can be surprising.