I totally agree with Christine that you can backup images to your own hard drive (or a separate hard drive) and Filezilla is great for that. My only issue with that is that if you had to rebuild your symbio site, you have a massive amount of data to upload from your home to the webserver. It could be done, but for some, could cause issues with their ISP.
I’ve been trying to come up with an inexpensive way to cut out your home machine by using Google Drive. I think I am 95% of the way there as I find that Mover.io can do an incremental backup and it can be scheduled – hence you could set it to incrementally backup your image folder to Google drive every night. I’m working through a few teething issues but I’m sure it will work.
I then back up all the rest of the folders (except core WordPress) and the database using UpdraftPlus – which again is automated to a schedule.
Steve