You can currently buy 250 $1 coins for $250, or $500(2 boxes) from the US Mint with free shipping and handling and pay with any major credit card. The purpose of this is to help promote circulation of these dollar coins as there is an unwillingness of many banks to provide them to business customers free of charge.
To get more information visit: http://catalog.usmint.gov/webapp/wcs/stores/servlet/CategoryDisplay?langId=-1&storeId=10001&catalogId=10001&identifier=8100