What I think NASA should do is:
Sell one orbitor. This comes as a package which includes access to all the infrastructure needed to launch and operate the Shuttle. If government wishes to charge various fees per usage basis associated with operating Shuttle there should also be available a realistic alternative- the Orbitor owner can hire it's own personnel.
The reason for selling the orbitor should not be to save money in short term, but rather to prepare for a complete transfer of the Shuttle to the private sector which at the same time guarentee that NASA will have means of getting crew into space safely.
Once it's demonstrated that the one orbitor can operated privately, what is learned can be used to allow NASA to rationally transfer the whole shuttle operation over to private sector. Once this is done NASA will probably end up saving a billion dollars or more per year.
So that's what you do with the Shuttle and you do this right now- don't waste anymore time.
Next NASA should announce it's intending on going to the Moon to determine if there is actually water there and determine if could be commerially able to mine the water. The NASA lunar mission should cost about 3 billion dollars- definitely less than 5 billion and it should take around 4-5 years to complete. NASA should go to Congress and ask for addition funds for this project. NASA should explain that NASA intends to work with the private sector- and this will mean that there could be private logos on space hardware which will be associated with NASA. And that NASA will be taking the lead in this mission but not neccessarily commanding it. NASA role will be trailblazing for possible future commerization, and this means the Lunar mission will be focused on mainly using "off-the-shelf" type technology.