How much to install a home surety system? I have 18 window and two doors and live in a...

I have 18 window and two doors and live in a to a certain extent nice neighborhood. There are existing door alarms and a previous system with two keypads, but it have not been turned on and I'd see in your mind`s eye a new company would probably want to rewire everything, especially since the window have simply been replaced. Does anyone know the average cost to install a deposit system plus or minus monthly monitoring? Thanks!
Answers:    Nearly 5 years ago I had someone try to break into my home. It be late at dark and the I had the lights past its sell-by date, but I wasn't asleep yet. I hear someone trying to pry open the pay for door. I sneaked into the living room and switched on the outside lights. It scared the burgler and I saw him illustrious tail it out of there. . I afterwards called a few burglar alarm service surrounded by my city and they all give installation and monitoring quotes. I suggest you call a local home securty installer to bring back your questions answered. http://www.homesecuritysystemratings.com Almost every alarm companies run a free installation special, so inquire roughly that too.
When I bought my townhouse, the previous owners had an alarm system installed. The window (about 10) plus 2 doors and a sliding glass door be already wired. I used a different company who just switched the major control box and the 2 keypads to their own system. They didn't touch any of the wiring. (I used Brinks.) I don't remember how much they charged but it be cheaper than re-wiring. I pay around $26 or $28 per month for monitoring.