Upgrade from 9Pro

Been a Cubase user for over 6 years.
Why is upgrading to a higher version, so frigging expensive?
I’m running 9 Pro.
Looking to upgrade but, my machine is running pretty good,
I can’t seem to find an upgrade to 10 Pro

So they can pay the programmers & the electric bill & the office space & the leprechauns…

Because they only sell the current version.