We do not offer license transfers. That's a bit different from prohibiting someone to sell something. Important distinction.
Not transferring licenses is a huge part of what allows us to offer upgrade pricing for loyal customers. Owning a license for the software is what allows us to offer free technical support and cheap product upgrades.
If you sell your physical copy of SONAR to someone, we're not going to recognize them as being the owner of the license. They will not receive technical support, we will not unlock their products for them, and they will not be eligible for applicable upgrade promotions.
I know there are a lot of mixed opinions regarding this topic and different laws in different countries. People love to argue EULAs etc. Regardless, what's most important here is that we've built our business around providing loyal customers with great support and cheap upgrades. Intentionally side-stepping this hurts our business, which as an end result hurts our product and our customers.
Also, I can't even begin to tell you how upset people on the receiving end of buying used licenses tend to be. I personally wouldn't want to be on the other end of that :)