hi! Thanks for the link but maybe my request wasn't clear enough.
That is a collection of 10 characters.
Many creators here create special "Bundles", group of assets, containing several packs, that can be bought in bulk by paying them once. Typically there's a little discount since you're buying the licenses for all of your assets.
That's something Itch.io lets you create. For instance, you could decide a price for everything on this page (https://bdragon1727.itch.io/) and let people purchase every asset in that page by paying once a price of your choice.