Do you honestly think a car with that kit from Amazon will pass the NHTSA requirements on backup camera?
Huge part of these costs is the regulatory compliance. Any part on the car is subject of various regulations from safety to after market support to environmental requirements (will your Amazon camera work in 125F ? in -50F?).
I don't see how it follows. We figured how to make rockets a longer while ago it still does not cost $50 to send stuff into space.
If that kit was enough then the manufacturers would just send it together with the car for dealers to install and comply with the regulations for $50 instead.
