Firstly - there are numerous professional CCTV companies with good customer support and experience who sell on ebay - this guide is strictly a warning about the CMOS type systems which have stated to appear - none of which appear to be being sold by any CCTV seller but mainly by sellers whose main product range has nothing to do with CCTV.
We have had several customers "caught out" in purchasing some of these systems as the listing format makes it very difficult to see what is actually being sold. By listing the equipment generically - ie: Night Vision or Infrared camera & DVR and not stating the actual details of the cameras and DVR being sold, these systems appear to be a good low price option for a CCTV system, however it is unlikely that these systems would meet most peoples requirements, however simple.
By using extremely small fonts when listing the specifications or by not listing the specification at all, it is difficult to see that the actual cameras being sold are not only extremely low resolution 380TVL cameras but are also 1/4" Cmos Image sensors not CCD cameras. A quick internet search on CCTV cameras will show just how poor image reproduction is with cmos cctv cameras which is why within the CCTV industry they are likened to cheap webcams (which actually tend to use higher spec 1/3" Cmos sensors).
Another discrepency which is hard to spot, is that these listings state that the DVRs support USB backup but don't explain that this is only achievable by connecting the dvr to a PC via a USB cable and it's not possible to backup onto a USB memory stick.
As with any Internet purchase, please ensure you are buying a product from a reputable seller, that a contact telephone numnber is provided - Not Mobile, and if possible contact the seller via phone or ebay messaging and confirm that the items available are actually suitable for your requirements.
Many thanks for your time