Ddiskrices.com crawls amazon data. Has filters, shows price per GB/TB, makes for a really good tool to find storage at good prices.
Serverpartdeals.com sells recertified/refurbished Enterprise drives that were usually used in data centers. Makes for much cheaper drives that usually come with a warranty, but i'd advise going this route only if you're working on a RAID system and have spare money to be able to quickly replace drives in case of failures.
Backblaze has HDD and SSD data reports you can check. Interesting data to have.
Backups on installgentoo.com
Data recovery on installgentoo.com
Data destruction on installgentoo.com
Only semi-related, Home servers on installgentoo.com
Don't forget the 3-2-1 backup strategy; 3 copies, 2 on different types of media, 1 offsite.