According to the Congressional Budget Office
the public option premium costs for a family of
four with an income of $66000 would be $8300.

Here is a link to a letter from the Director of the
Congressional Budget Office to Rep. Charles Rangel
dated Nov.2 that contains a table outlining the cost of the public option.

http://www.cbo.gov/ftpdocs/106xx/doc10691/hr3...

Here is a link to the CBO blog providing more information
and examples.

CBO’s Analysis of Premiums Under the Chairman’s Mark of the America’s Healthy Future Act

http://cboblog.cbo.gov/...