You can contact firstname.lastname@example.org or fill out this contact form https://www.denodo.com/action/contact-us/ to request more information about prices if you are interested on getting a full version of Denodo Platform.
Regarding the Denodo express licenses, they are just valid for a specific period of time, usually one year. If you want to continue using the express version, you could download a new express license in the [Denodo Express site](https://community.denodo.com/express/download). If you have used the Denodo Express edition for a while, I would recommend that you to try to use full version by requesting a free-trial or an evaluation license, as you can explore the Data virtualization potential with the Denodo Platform without any capacity restriction.
Hope this helps!