If you can’t afford a 4TB HDD and postage, then I would suggest that you won’t be able to undertake the restoration.
You need at least twice the space of the scan to be able to do a restoration, just for working files, and you need to be able to output the final result.
That is part of the reason I am so broke, the need for working space, and preferably fast working space is a huge requirement, but one you really can’t do without.