You definitely have a case and if you can arrange someone to do the IT I’m sure the company will definitely go along.
I have a 3 TB disk which is about half full over 4 years of work. And that includes:
- properly naming all files before storing, removing older versions as well as temporary workfiles
- archiving 3D mesh and STEP/IGES models as well as render files
I recommend for a studio to have 5 TB per fte employee.
Also I am creating a double backup of important work, with DVD and preferably Bluray, to store at another physical location.