So, trying to figure out what is the best way to solve this. I have a client who wants to list 'past auctions' and within an auction there are several items (with images, title, explanation)

As an auction exists of several hundred objects, it makes sense to be able to upload a CSV to fill the auction. All the images need to be added during 1 large upload too.

I found solutions to fill a collection with data. But as we need to make first an 'auction' and then fill this with all the objects, this would make then a collection within a collection?

So basically you would have an overview page with all the past auctions, when clicking on it, you would then see all the items within this past auction.

How would you guys/girls solve this within Statamic?

I was thinking of 1 large database and adding categories (auction) to it, and then list the items per category. A category then has a title and some subdata.

An example of what the structure should be approx: https://www.68-art.com/en/past-sales (overview) https://www.68-art.com/en/catalog/105736? (detail)

Thanks for your ideas!