I'm doing fairly well with the base, free, storage amount Apple gives and since I am an Office 365 subscriber I also have 1TB of storage space that I use with OneDrive and of which I'm only using about 10% of it.
Have you had any issues with OneDrive. I've debated upgrading my Dropbox to the Pro account, but I have a hard time justifying with my Office subscription.
I have to use Dropbox for a few apps so I can't get rid of it, but I'm thinking of using my 10GB of Dropbox for in-use files and apps, OneDrive for selective sync backups of some movies, Music, photos etc. (to supplement my local plan), and iCloud Drive for just some app folders.
I can't see paying for Dropbox Pro for selective sync backups when I can use Onedrive for it.