I actually purchased my Viper alarm, tilt sensor and shock sensor from Amazon. But, I went to Best Buy for the installation because I understand that they are THAT good at what they do. In addition, because Best Buy installed these items, they guarantee the labor for life. And we all know how electronic items do not last forever. So that means if the brain of my Viper system goes after a number of years, and Viper refuses to stand by their product, which I've read to be true, if I buy another one, Best Buy will install it for free. I think that's a pretty good deal.
So when the installer mentioned to me how this 10 dollar item is superior to the cheap quality ball bearing tilt switch that comes in the Viper box, I went with his suggestion. I have absolutely no reason to doubt him because I have been a Best Buy customer for many years.
By the way, Best Buy may not have the lowest prices, Amazon currently holds that honor, but I know they have fabulous customer service. Trust me, I have dealt with them for quite a while and I have never been disappointed.