In case you missed Prime Day, and unfortunately, it is still not because of the death of Optimus Prime, you can still get some decent deals. Every prime day and Black Friday sales events, I look for one or two specific items that I always need more of every year, that's digital memory. These are some I found post-prime day, which are still pretty decent.
WD 4TB "My Book" External HDD $98.99 - which is a steal per TB and what it does overall.
WD 2TB Elements Portable HDD $57.99 - I have two of these I use for general purpose backups and they work really well.
Sandisk Ultra 64GB USB thumb drive $11.99 - This is the new generation, I have several I use at work, on key rings, they are really good to go and can be secured using passwording and encryption.
Samsung 64GB USB key ring thumb drive $11.99 - I have two of these on my keyrings, one at work. They work really well for having a thumb drive you can beat up on your keys, can encrypt, and can use as a general-purpose tool for data management.
Any way you slice it, you should always have double and triple-redundant backups of all of your valuable digital files. The current industry standard is to have at least two physical backups, one off-site, of every valuable digital file, backed up every 3 months. If you take photos on your phone, if you literally do anything online and save files, if you produce content, anything at all, do yourself a favor and backup everything on your local drive, then on two different external drives, one being stored (and secured) elsewhere, swap them out every 3 months. I know that's difficult, but memory is not as expensive as it used to be and it's very much accessible now. Do yourself a favor and do it now before you start to hate life because you didn't back anything up and lost valuable data you can never regain. Do not trust the cloud for your valuable data, especially if you will suffer serious issues if you lose it.