Hi Bert,
Please refer to the below,
https://www.mendix.com/pricing/
https://docs.mendix.com/developerportal/deploy/mendix-cloud-deploy/#free-app
https://docs.mendix.com/developerportal/deploy/mendix-cloud-deploy/#resource-pack
For more details please contact the Mendix Support Team https://support.mendix.com/
Hope it helps!