What could be the right business model for a FREE data marketplace?

We have a baby business https://datasn.io that we want to transform into a grand website of datasets offered FREE to users.

Users will also be able to upload and publish their own datasets that can be viewed, searched, diagramed, forked, or pipelined on the website. They can talk and comment on each other's datasets, create something off them and share with the community, just like a GitHub of datasets.

The problem with datasets is that they take up tremendous amount of spaces and are pretty expensive to be set up for queries and searches that consume quite some computing resources.

How can we:

1. Motivate people to share their datasets
2. Make it profitable to open up the datasets FREE

Or is it financially impossible?

My ideas thus far:

1. Don't make it zero FREE but nearly FREE with a very cheap access fee for each dataset, in the range of $10 - $50 which will be used to cover infrastructure cost AND to pay to the uploader for motivation.
2. Browsing the data is FREE on-site but charge for exporting and downloading to a certain format, OR for pipelining to another application such as WordPress to create a website off the dataset, OR for other tools of data analysis or data search engines.

So owner sets a rate per row, and buyers pay a download fee every time he or she downloads the dataset, determined by the number of rows downloaded.

Is this viable in a business sense? I'm from technical background so I'm not sure.

Would really love to know your ideas and what a viable business model could be for this.

Thank you!