Within Europe and if you're not at Hetzner already, Hetzner Storage Boxes[1] are very competitive. 4 Euros per month for a terabyte, throw borg[2] with compression + deduplication at it and it'll take you far. Especially if your databases are not changing that much, then borg can make that terabyte of storage a lot bigger.

1: https://www.hetzner.com/storage/storage-box/

2: https://www.borgbackup.org/