Best practice - how to delete and archive pages

Many of our editors feel uneasiness when deleting pages in EPi and instead choose to unpublish them. The reason is partly that editors do not know if they will reuse the files in the future, partly that they want the ability to see what they have previously published. With time this makes the tree completely full of unnecessary old material that clutters the tree.

I would like the editors to feel completely confident when deleting pages and be sure that they can find their old stuffi.

Any ideas how this can be achieved? I´m thinking of something like a connection to some kind of archive that that regularly and automatic makes copies of the site.