Timely post.
I was about to make one because iDrive has decided to double their prices, probably because they could.
$30/tb/year to $50/tb/year is a pretty big jump, but they were also way under the market price so capitalism gonna capital and they're "optimizing" or someshit.
I've love to be able to push my stuff to some other provider for closer to that $30, but uh, yeah, no freaking clue who since $60/tb/year seems to be the more average price.
Alternately, a storage option that's not S3-based would also probably be acceptable. Backups are ~300gb, give or take, and the stuff that does need S3-style storage I can stuff in Cloudflare's free tier.