What do you want to do with the HDD’s? I have a bunch of crap saved on mine, but nowhere near 12TB. Also I rent some drive space (Hetzner Storage Box) for server backups. That adds up over time but you don’t have to spend a big chunk all at once, and HDD prices might eventually drop again.

Feel lucky that you want HDD rather than SSD. SSD prices have tripled or quadrupled while HDD has not even doubled, per the graph someone posted.