As the license guide says we do only get one free Marketing installation for a tenant, when you have that 10 CE licenses. So how to setup a development environment for this? There needs to be a development instance, a testing instance, a staging instance and a production instance. Our free Marketing installation and the portal instance will go to the production instance. How to get the Marketing solution into dev, test and staging and a portal instance for each?
The only answer I know to this is purchasing additional marketing applications (421,60€ each). Since the licensing guide does not say, that you automatically get another portal instance for each marketing application, I am afraid you also need to buy additonal portal instances (also 421,60€ each). If that's the case it sums up to 30.355,2€ per year, without having done a single customization or one line of code. Despite the immense costs that can come with the marketing solution (depending on the number of engagements per month) I am shocked about that additional basic costs you need to spend only for having a tenant that is able to to fit the needs of a development lifecycle as it is recommended.
So this can't be the answer...