If the data really isn't important, then that is exactly what cloud storage is for. You can get a great price on a lifetime subscription for a tenth to a quarter of the price of a NAS+HDD's and the maintenance needed to keep those TB's of data 'live' over a few decades of use.
Just being saved from the headaches of not having to be up to snuff as the security/internet/network landscape changes day by day and year to year are worth a few hundred dollars to me. Especially for non-important data.
For actual data, the opposite of the above is true, of course.