Storing a collection of this size requires substantial storage capacity. Options include:

In summary, a complete 3DS ROM set would likely be several terabytes in size, requiring significant storage solutions. The exact size can vary based on the factors mentioned, but it's clear that it's a substantial undertaking, both in terms of storage needs and the effort to curate such a collection.

Depending on how the set is curated (regions, duplicates, and file types), the total storage requirements vary: