Right now (2012 launch price) it would cost about $500 billion to launch the equivalent mass with Falcon 9s. They expect to cut the current cost in half, and with a very high launch rate Musk has said it could be 1/10th, but the required launch rate may not be achievable.
The entire shuttle program cost around $200 billion in 2010 dollars.
The entire shuttle program cost around $200 billion in 2010 dollars.