Could you do it - yes. It would clearly violate the licensing for you and for the person selling it, and more than that it would violate the trust that the Cakewalk folks have given us for decades now, where they allow us the freedom and the really unheard of capability to have it installed on multiple machines, with really nothing but our collective 'word' that we will only run it on a single machine at a time.
I don't know about you, but dongles and restrictive licensing are pretty much universally hated, and it has been expressed in these forums many times by lots of folks that Cakewalk software users GREATLY appreciate the way Cakewalk has chosen to deal with licensing.
So I guess in the end, YOU have to decide if your interest in obtaining a 'used' copy of any of their software outweighs the value you place on your word, and the same could be said for whoever might contemplate selling or even giving away a used copy of any of their software.
Every Cakewalk install requires the user to explicitly check boxes agreeing not to sell or transfer the software under any circumstances.
Cakewalk works hard to survive in a competitive market, and they would cease to exist if enough people gave away or resold copies of their software. Perhaps prior to that, they would attempt some more extensive software license protection mechanism, such as dongles or worse. I certainly would not care to see that happen, and hope others feel the same way.
I recall a small number of 'example' cases, where individuals were sued successfully by software companies, and while it not likely to be determined to be a max fine for it, each instance of piracy of software does include up to $100,000 and/or up to a year in jail. However likely or not likely any legal action would ensue, for ME, I will continue to respect and honor the trust Cakewalk places in me, and I value the continued existence of their products and am quite happy to play by the rules.
Bob Bone