What is reasonable money? AWS Glacier Deep Archive is around $1/TB/month. Since it includes Multi-AZ replication for "free", you'd have to store multiple tapes in multiple facilities to get the same durability with tapes.
Retrieval costs are additional of course, and depend on how quickly you need access to the data, but if you just want to store data long term in case of disaster, $1/TB for multi-AZ replicated data seems like pretty reasonable pricing.
LTO-6 tapes hold 2.5TB of data (uncompressed), assuming you store 2 for redundancy, you'd need to find a place that will store them for $1.25/tape/month to break even, plus you're paying $25 for the tape itself, so over 3 years, that's almost another $1/month/tape. Plus the tape drive itself is around $1500.
You can use newer tape technology for better economies of scale, but your buy-in cost is higher due to the higher price of the tape drive, so you'd need a pretty high volume of data to break even.
Glacier cost in the cheapest region is 3.6$/TB/month. Plus at least 50$ to download that terabyte once it's needed(if hardware that you're backing up is not in AWS), and I don't even factor in retrieval costs. You can get HDD storage cheaper than this(twice as cheap with some providers) if you are willing to use dedicated servers. And they come with unlimited traffic. And you can use hardware there for something. Glacier is expensive AF.
And its awesome until you notice that just the transit fees to restore it work out to roughly $100 a TB. Which even for someone with a small auto loader (10-20 tapes), quickly buys a new tape backup system should they ever have to restore 100TB+.
So, if your 100% confident you won't ever have to restore it, its a great deal. I was considering it for my personal backups but the ~3-5k a full restore would cost me is unpleasant on top of the $30-50 a month the storage would cost me. Over a 3 year timeframe that is $1000-1800 just in storage fees. So, maybe I will just buy another USB JBOD...
I suspect that over 100T, tape is still much cheaper, especially if the offsite storage is a fire safe at the CTO's house. Once your in the few PB range its a no brainier and actual offsite storage services start to look inexpensive. https://spectralogic.com/wp-content/uploads/white-paper-iron... says that its ~$1 a month per tape to store it at iron mountain, but I'm pretty sure there is a nice volume discount, one of the previous places I worked used them for tape storage and the actual storage bill was a joke in comparison to the pickup fee.
Glacier is for storing records that by law you have to keep for a certain period of time (e.g. 6 years for expenses, tax & accounting, etc.) but that you have no intention of ever retrieving yourself. It's not a cheap backup solution.
Who is accessing their off site backups regularly? I spent 7 years of managing IT for a 500 person company and we never needed to pull in the offsite backups, those were for disaster recovery. After decades of managing my home backups, I've never had to pull in the off-site backups (which started as CD's (the DVD's) mailed to my parents, then a hard drive, and now cloud backup (not AWS)).
I always have local backups which I'd use to recover a deleted file or crashed hard drive, it would take weeks, maybe months to pull down my cloud backup unless I pay for a hard drive to be shipped to me (or in AWS's case, a Snowball, I could have 100TB restored in under a week using a Snowball)
This is deep archive offsite tape storage, not something you'd need to restore often.
When I last managed offsite tape backups, I never planned on really needing to retrieve the data -- I had the data on disk and on the most recent tapes. (I did do periodic restore tests)
If I had to restore the data, I wouldn't care how much it costs (within reason).
Retrieval costs are additional of course, and depend on how quickly you need access to the data, but if you just want to store data long term in case of disaster, $1/TB for multi-AZ replicated data seems like pretty reasonable pricing.
LTO-6 tapes hold 2.5TB of data (uncompressed), assuming you store 2 for redundancy, you'd need to find a place that will store them for $1.25/tape/month to break even, plus you're paying $25 for the tape itself, so over 3 years, that's almost another $1/month/tape. Plus the tape drive itself is around $1500.
You can use newer tape technology for better economies of scale, but your buy-in cost is higher due to the higher price of the tape drive, so you'd need a pretty high volume of data to break even.