There is more to comparing Home Security Alarm Systems then meets the eye. One of the biggest costs is the monthly monitoring fee (assuming you are comparing monitored alarm solutions). Many companies offer free equipment, but charge more per month to monitor it, so your up front costs are lower but your lifetime costs can sometime be significantly higher.
The top two home security alarm monitoring companies in the US are ADT and Protect America. You can see a comparison chart of their upfront and total costs on our home alarm comparisons page.
Continuing with the monthly monitoring service fees, note that some charge more if you have more sensors. Many will quote a base price with a single control panel ad a few sensors, but you need to count your windows and doors, cameras and motion detectors, etc. to see exactly how many sensors you will need to have monitored. Only then can you find the true cost of your monitored alarm solution.
