I installed my own wireless alarm system in about 3 hours programming it using my laptop. My monitoring company is out of El Cajon called Alarm Relay. For $9.99 a month I get full landline monitoring. For a DIY install check out some forums on the web for guidance.
It gives me piece of mind in reducing theft during a break in as well as reducing the chance of a full forced entry by having the alarm armed while in the house using the “stay” mode.
The major alarm companies charge too much for install and monitoring. My whole house is covered with all 1st flood windows and doors, 3 PIR’s and glass breaks for under $400. Ebay is a good source for parts once you decide on a system.