Insurance editor to help you answer, more questions can be answered online.
This can not be directly compared, the nature is different.
Social security is the principle of social justice, not the principle of personal justice, so there is no question of whether the individual is cost-effective.
Commercial insurance is the principle of individual fairness, but because the individual insurance base is far less than the social security, the contribution is also relatively high.
Generally, social security is used as the basis, commercial insurance as a supplement so with. The use of social security alone is not enough, because social security is only the basic insurance is not a package. Commercial insurance alone is more expensive.