Just a couple of points from someone who has used Sibelius for many years. If you are a student or a teacher there are cut price versions available.

Secondly Sib is now on version 6 or 7 or maybe even 8 by now. All the earlier versions work perfectly well. I still use version 3 on my oldest computer and it does just fine. I have version five on another computer and can pass files in either direction without problems. Try Ebay for early versions of Sib. You might be surprised.