Their license has changed as of last year. You no longer purchase ST3, but a license to ST for 3 years (including updating to ST4), and then freezing on that version of ST when the 3 years are up. They aren't selling software to users with ill intent.
That seems like an aweful model. If ST4 still takes another 4-5 Years until a proper stabel, I'm basically unable to update with a licence bougth today, despite the high price?