Beepster, I wouldn't worry too much. The trend has been to make the upgrade price very low. It used to be $179. Than with 8.5 it went down to $99. Expanded came in at $49 on sale. So I don't think you will be locked out due to price. Than you can wait a bit for a sale if you want.
Early adopters always pay a little more. But they get the product to use earlier. Plus they are able to be helpful to other members about it. Answer questions and find the bugs.
Your X1 will not be unusable and you still can make music with it until you are able to upgrade. So don't be upset or concerned.
Besides by watching this forum you will learn what works well and what is broken. It will prepare you for what will be coming.
I look forward to its release and hope it will live up to expectations. It sounds to me like an evolution of X1.
I was hoping for better notation though.