However, this argument is pretty much a lie in any event, because the "rental" model isn't you're only option, and the price of Office hasn't gone up.
Of course it has. You were able to transfer licenses from one computer to another with the previous Office versions, that's gone. You need to pay up for every PC install the full price again now, even if your old PC got damaged and you (or the repair service) only installed a new mainboard there. Price increase.
Older versions had dual licensing ("2PC/1 User") - one Office license was valid for a desktop AND a notebook install. That's gone. Price increase.
The family packs for Home and Student introduced with Office 2007 (3 licenses for around 150-160$) are gone as well. Price increase. And a really hefty one for this group. Particulary if they don't need Outlook.