You mean electricity bills for powering the storage? I guess buying 100pb worth of storage disks would be pretty expensive enough but since it’s an archive there is no need to keep it powered 24/7, just turn them on only when you need to. It’s just a hypothetical situation anyway, it’s a thing I wish to have access to; only an experienced sysadmin can actually maintain such great archive or its copy/backup

If you’d download the whole wikipedia be sure to download the whole commets section for each article to have a perspective on discussions on conflicting reasons for edits. Also include all the wiki media materials for all of the public domain literature, project gutenberg, entire archive.org, a good offline OS to be able to consume all of the information and you’re golden