WordPress.ORG does not sell any commercial products at all, and has no information about them either.
There is, however, a list of GPL theme developers/vendors - which is a good place to start:
But so far as specific themes or developers, you'll have to do your own research and due diligence. Ask questions, look at websites and support forums (if available), use Google. Look at how often themes are updated, make sure there's good support if you are likely to need it. Read the fine print :)!