If by "last scripts" you mean the ones that JMS wrote that go at the end of Crusade S1 then everything that Lyta said is true.
If you mean anything after what was filmed and aired, then there are some *legal* copies of Fiona Avery's script, which featured good old Al Bester, floating around. It was to have been the next one filmed when production shut down. For a while Ms. Avery was selling autographed copies directly (maybe she still is at her personal appearances, for all I know), and these are legal. Any photocopies or electronic transcriptions of this are illegal, however.
Of course, whether anyone who has one of those legal copies is willing to part with it is another matter entirely. /forums/images/icons/wink.gif
I know that I don't intend to sell mine. /forums/images/icons/grin.gif