You can make a collection to sell more than 1 file as a group for 1 single price.
1. Turn on power mode in your dashboard
Go to my config and switch to admin mode / power mode.
2. List files
Go to the tab "files" and on the left click "list files" which should bring you to this page.
3. Create a collection
Select the files you'd like to add to the collection and click "add to collector" at the bottom. You should see a notification at the top that says "your collection notepad keeps X item(s)!" Click the link X (should be a number).
In the collector click "create collection product" after you have finished adding products.
4. Edit the collection descriptions