If you are just self hosting for your own use, just stick with letsencrypt or self signed certificates.
The paid certificates are for businesses where the users need to trust the certificate. They usually come with warranties and identity verification, which is important if you are accepting payments through your website, but it’s just a waste of money for personal use.
SLC drives have around 100,000 write cycles. Most consumer SSDs are QLC now and those have less than 1,000 write cycles. They also tend to write slower than a mechanical hard drive when the write cache gets full. Some of those drives can be modified to run in pseudo SLC mode. That trades capacity for speed and write endurance.