Layers of protection for your home.
I have plenty of firearms, but if someone is able to sneak up on you in your home or kick your door in before you have time to react then your in trouble. Here is a list of suggestions to help your first alert system. Some are affordable, some aren't.
Hidden- Would be things such as hidden video cameras that uploads to the internet. Sensors in your yard that only alert you, instead of alerting the criminal. A fence that has a half opened pad lock on the outside, but a hidden lock on the inside of the gate.
Locks that are not bump proof on the outside, but a hidden remote operated lock on the inside.
Overt- Security system decals on windows and a sign in the yard. A big dog in your yard. No tresspassing or will be shot signs. Gun racks on the back of your pickup with no rifle in them. Size 16 shoes covered in mud at the front door.
Along with these things, you could have thorny plants around the windows. There are also sensors that you can put in the ground that alert you us an intruder outside.
Storm or burglar doors. Bullet or scatter resistant windows. Burglar bars on windows or doors. There are better burglar bars than others, the burglar bars that can be taken with just a screwdriver or wrench are okay, but I prefer installing them inside the window. There are burglar bars that are installed, inside the home instead of out, these are much better.
You can also get a home alarm where all the doors and windows are monitored, then you can get vibration sensors on the windows in case someone breaks the glass instead of trying to actually raise the windows.
Basiclly, if you have the money or know how you can set your home up to be a death trap for any criminal.
A cheap way to protect your home from kick door invasions is to wedge a board between the bottom of your door and the bottom of your wall. Some homes you can do this and others you can't. You could even have a brace installed that is bolted to the concrete in your floor, then a bar would extend to the bottom of your door.
Then there are door jamb reinforcement items you can buy. Metal door frames. Solid doors. Etc.