Thanks for reaching out again here!
You can add the Cost field to the Filter Bar by going to Events Settings < Filters and checking the Cost filer from the left. It will then appear on the list of Active Filters on the right.
Let me know if you have any further questions on this topic!
Perhaps I’m not quite sure what you’re trying to achieve. Would you mind providing me with some screenshots?
Are you looking to add tickets to events from Facebook and Meetup after they are imported?
If so, you can edit these events in their Edit Event page and add necessary information there.
Can you also provide me with the URLs that you are trying to import, if you think that something may not be working properly on your end, so that I can do some testing as well.
Let me know if you have any other questions on this topic in the meantime!