You’ve got until 19 September to get Final Draft version 9 for $149.99 US, approximately 40% off, from the official site here.
The sale includes both the Mac and Windows editions: for Mac you need OS X version 10.7 or later – that’s better known as OS X Lion – and for Windows you need XP or later.
Final Draft doesn’t exactly stretch your computer: it’s funny how old-fashioned the software looks. I have version 8 and don’t really use it enough now to warrant going to 9 nor can I really see much of a difference in the upgrade: there isn’t a killer must-have feature.
But it’s a solid script-writing word processor and if it has more and better competitors today, it is still true that Final Draft is the nearest thing to an industry standard.
If you are an existing user, by the way, you can upgrade to version 9 for $99.99 on the same official site’s store.