This is some traumatic experience you went through!
I think if I didn't own a gun I would consider this as an option to protect my family because you never know. And ransoms are like drugs, you take them today and tomorrow you want more when the money is done.
How do you know they won't comeback, protect your self and everyone close to you.
Did you go to the police after, maybe someone saw something and these guys can be found with any details provided to them.