hi,
i can give you an initial estimate (based on nothing else but your raw data), like 100GB for data and 200GB for work and temp. You should also keep in mind the sizing for your users SAS folders.
by the way, everything will depend on:
the amount if your users
prediction about the growth of your data
other datasources more than raw data
other variables specific for your business needs
keep in mind the second consideration: the future. I would never advise to stick only to the present, but keep an eye on the future, so you won't have troubles with your disks in the close future: SAS data and requirements grows pretty fast!