Upgrade path from FCP 4.5 to 5.xx

On the Apple page/Final Cut Pro/Buy Now
it has options for upgrade from 1,2,or 3
OR buy new.

Is FCP 4.5 an option to allow for upgrade?
It is only Motion I want to upgrade, but
it seems one must upgrade everything.

Please advise

All previous versions of Final Cut Pro including 5.0 are now priced at $699.00 for an upgrade to 5.1. I just called Apple and checked how they are dealing with this now that the lower priced deals are gone.

Wonder what the next version upgrade will cost for 5.0 or even 5.1 users? I guess we will see in about 14 days?