Repealing Obamacare may be politically popular, but the current proposals are going to be costly.

Republicans are moving ahead with campaign promises to repeal and replace the Affordable Care Act, known to most Americans as Obamacare.

Many of them have attacked the landmark law as too costly. But a back-of-the-envelope estimate finds that the replacement plan being floated would end up costing the federal government and additional $600 billion over 10 years.