This is a tough question because it depends on how you feel about a very, very unlikely event (a fire starts at all, it is at the end of the house far from the central detector, we are away when it happens). If I were making the decision, the cost vs. the very unlikely scenario would not be worth the extra expense of the $150 detectors. Also, you may not stick with the alarm company, and then you would have wasted the money tying them all together. I suggest going with independent detectors and save some money, too.