Backblaze B2 Offers Dirt-Cheap Cloud Storage for Half a Penny Per GB a Month
There isn't much you can buy for less than one cent these days, but you can store a whole lot of files in the "cloud" for $0.005 a month with
Backblaze B2 is similar to Amazon S3 (which starts at $0.022 a month) or Amazon Glacier (which
costs a penny per GB
Like Amazon S3, Microsoft Azure, and Google Cloud, you pay for both storage and retrieval (downloads). Downloads cost $0.05 per GB, so this isn't really a Dropbox replacement or for frequently accessing files. But you could store 100GB of photos or videos there for safekeeping for just $0.50 a month, which is pretty cool.
The service comes with a web interface to upload or download files into your buckets, as well as alerts for when you're reaching a storage limit you said. If you need to download a big bunch of files at once, you can get a flash drive with your files sent to you (128 GB) for $99 or a USB hard drive (3 TB) for $189.
In any case, if you sign up you'll get 10GB of storage to try B2 out for free.
B2 Cloud Storage | Backblaze