1) You can use the DH2 beta for free. You don’t need any key.
2) Existing DH1 users will get a discounted update if they want to upgrade to DH2.
3) It costs lots of money to develop software. DH2 is completely re-developed from the ground up. No company can afford to redevelop and add features without charging for updates. This is pretty standard practice in the software industry. If you don’t want to upgrade, you don’t have to. DH1 will still be actively developed for the next year.