One can buy a second copy and donate it to the Library or give it to a friend. Now it's offsite, like all backups should be, and one doesn't advance technology much to achieve this. Depending on how you attribute a "cost" to the time it would take to make a duplicate of a physical copy, it may even be less expensive.

Photocopiers and OCR and both things which people have used for this purpose.

The time it takes to use them for that purpose though... ugh.