4. It doesn’t matter if this is your first time installing your home security system or you’ve done it countless times, going through the instruction manual is a ‘no brainer’. They are included for a reason and they should be followed if you want everything to run smoothly. The wireless home security systems of 20 years ago were notoriously unreliable. They produced so many false alarms that many homeowners stopped using them. That’s all changed. Today you can buy DIY home security systems that have professional grade wireless security equipment that’s extremely reliable, easy to install and affordable. Basic DIY home security systems start at about $225 and top out at $800 or so. If you add wireless smoke/heat detectors, plan to spend about $1,300 for DIY alarm systems. That’s about half of what a professional alarm company would charge. Monitoring service, which notifies the police or fire department, can cost $40 or more per month.