As for the space shuttle main engines, those are now free. Nasa advertised them for 400,000 to 800,000 US dollars each in December 2008, but no one expressed interest. So now the engines are available, along with other shuttle artefacts, for the cost of transportation and handling.
As a victim of too many poor instruction manuals (especially on Christmas Eve), the last line strikes fear into my heart :-)
Simply place part number SFRT-HGTY-0037654-B into perfect alignment with part number HYGT-KJIL-4588900-G and tighten each of the 250 bolts to exactly 14 pounds of torque, tightening in a clockwise fashion alternating over 7 bolts in 2 pound increments...
I saw that on the news too and told my wife I wanted one to put in the back yard to play in but my shop building is only a 30x50 foot and it won't fit. I actually got to sit in one of the shuttles at NASA while doing a video there a few years back. they told me not to step on the controls since they were spare parts. Seats are kinda small anyway.