Hey @SGoodman - thanks for posting on our Community and happy Friday!
It's true that the shared folders take up space on all accounts that are members of the share.
If you need access to this shared folder without impacting your own quota, you can ask the owner to send you a shared link with view only rights instead of sharing the folder directly with you.
If, on the other hand, you need to upload back to this share, you can ask them to open a file request for you instead.
I hope this helps!