If you're looking for a top-notch musical notation/scoring program that's cheaper the MakeMusic's Finale or Avid's Sibelius, then Notion's slick-interfaced Notion 3 is well worth a look--and a listen. The sounds of the London Symphony Orchestra that are included in this $249 package are just as good or better than what's included with its rivals.
Notion 3's major strength is its interface. It's much better looking than the competition, as well as much easier to navigate and use in virtually every way. The program can't compete in the length of its feature-list, but offers everything most users will need and produces nice-looking scores. It supports MusicXML natively and the sequencer staff is well worth a look, even with the large download size.
Note: This link takes you to the vendor's site, where you must register to download the software.
--Jon L. Jacobi