Or if you don’t want to deal with upgrading it, you could just transfer some games, saves, etc. to an external hard drive before deleting them. It still wouldn’t be as nice as actually having a bigger hard drive for the PS4 itself, but it would be better than deleting them permanently.

Ya, they aren’t cheap unfortunately. ;-;
I’ve seen videos though on how to just build your own, looking EXACTLY like the arcade setup.