Yes converting to coins will save the government money, but not until after 10 years.
It would not take 10 years though. The Mint could easily make a billion dollar coins each year. They made 940,870,000, in 2007, so I bet they could do more, if demand requested it.
Plus for 2010, they printed 1,856,000,000, $1 notes and 95% of notes printed are to replace existing ones. So really they only need to print 92,800,000 $1 notes for increased demand. A very small # for the US Mint to handle each year.http://www.moneyfactory.gov/uscurre...figures.html
During Fiscal Year (FY) 2011, the Bureau of Engraving and Printing delivered approximately 5.8 billion notes at an average cost of 9.1 cents per note.
And I bet that 9.1 cents includes the cost of the $100 note, which is more expensive to make than the dollar note. I think I read somewhere that it is about 6 cents for the dollar note. I just couldn't find it.
And the dollar coin costs 18 cents to make.
Since the dollar coin costs triple what a dollar note costs, in about 3 years, there would be a profit.
It could easily happen next year. The US Mint already has the machines in place for it to happen. We just need the government to make the decision.