These days, with the advent of the entirely legal "recycled license market" coming out of the EU, I'd recommend buying the real thing for a song.
I've now upgraded at least 6 machines with Office 2016 Pro Plus for $10 US or less per machine using recycled licenses.
Brian - Windows 10 Home, 64-Bit, Version 1809, Build 17763
A great deal of intelligence can be invested in ignorance when the need for illusion is deep.
~ Saul Bellow, To Jerusalem and Back