I really hate that Apple switched to SSDs because they halve the hard drive space without affecting the price. I had to get a refurbished one to get 500 GB of space, I backup monthly to a 4TB drive (which also has all my fifteen years worth of files), another for my media, and an old spare 1TB for my iTunes. I try to keep as little as possible on my actual computer, I've been through enough computers to know better than that.
I ALSO try to make a point out of keeping my files organized as I go, I hope that you're doing that as well, Mac. There's no point in keeping all your stuff backed up if you don't know where to look for it.