You may be able to save some money taking into consideration the actual home security CCTV cost by opting for cheaper a cheaper CCTV system that still provides you with the coverage and capabilities you seek. Opting for a wireless CCTV camera system will cost less than a wired system and a multi camera system will cost more due to more cameras required.
If you are a qualified electrician or are confident in your own abilities, you may be able to install your own CCTV system, however it is always recommended a qualified electrician undertakes the work due to assembly knowledge and troubleshooting if any difficulties occur during the installation process.