The Word from Gostev
Have you seen just how much space a fully tooled up Share Point or two takes up? Shovel in some insanely large Exchange and Outlook .PST and .OST (multiple copies please - just in case)
Oh look SQL. Right we'll need backups of the tables and tran. logs and a few extra copies of all the tables for each minor version point since the early 2000s and for whenever a single row of data is input.
And you'll have several copies of every single photo taken by the organisation, massive wodges of video. Plus every scan made by every MFP since the dawn of time.
Each major data area will also have a copy (just in case) and one or more mistaken and mostly partial drag and drop copies in several other locations.
Multiple duplicate shortcuts will take up at least 1Gb on their own.
Then, there's the pr0n ...