According to healthcare.gov, the prices of Marketplace plans have not been set yet. Prices will be available October 1, 2013, when open enrollment starts and you can begin shopping.
Starting in October, when you use the Marketplace to compare plans you’ll see prices for all plans available to you. Prices will show any cost savings you may be eligible for based on your income.
Until October 1, you can find a rough estimate of costs and savings by using the Kaiser Family Foundation calculator.