Sort your data into stuff you absolutely need to keep (personal files and such) and stuff you’d be okay with losing (less important files, device backups, downloads you can redownload, etc). Then only back up the former. As for backup medium, ServerPartDeals often has some pretty good deals on storage; they were selling refurbished 12TB drives for $80 a pop a while back.
Sort your data into stuff you absolutely need to keep (personal files and such) and stuff you’d be okay with losing (less important files, device backups, downloads you can redownload, etc). Then only back up the former. As for backup medium, ServerPartDeals often has some pretty good deals on storage; they were selling refurbished 12TB drives for $80 a pop a while back.