Hello @Wietse_Sennema, and welcome to the community!
Here’s some friendly advise that you may not like, and which some consultants will certainly not appreciate. 
Airtable can do this pretty well with its API and integrated scripting environment. It also has pretty good support for charts and even Vega-Lite can be used to create advanced data visuals.
Airtable is not ideal as a dashboard platform; it’s quite limited in creating custom and personalized layouts the likes of which a marketplace would be expected to provide.
Airtable scores high marks on this requirement as long as the free tier of the solution is adequate for your business requirements. If your community must pay Airtable $24/month each, it will likely be ruled out as a viable marketplace development platform.
These requirements are complex; each has a long list of details that should be scoped and designed separately. However, Airtable is not ideally suited for payments and I predict there will be many challenges on this axis alone.
Like many consultants, I love a good challenge, but on this one, I would advise against it leaning more toward a platform designed for precisely this business model like My Marketplace Builder or any one of these open-source platforms.
Note - these platforms and services exist for one key reason - what you’re envisioning is not easy to build with off-the-shelf parts.
Best wishes on your new endeavour and be sure to let us know what you came up with!
