Out of curiosity why not just backup to a file and store the file for disaster recovery instead of spending all the money on a duplicate card?
Buy a small SSD drive and backup your 15 to that drive? Even a flash drive is possible.
This sounds like a simple solution, but I'm so old that copying cassette tapes was still a thing when I was in my 20's, and figured the process would be similar for CF cards.

I would still have to write them to CF cards in a disaster, so I still want to learn that process.
The willingness of everyone to help newbies like me with my limited skill-set has set me off on an opportunity to learn new things, and is much appreciated!
