Depending on the amount of data you have, might it not be less expensive than build the tape drive?

An LTO drive is easily $10.000. You can restore a lot of S3 data for that amount of money. Sadly getting cheaper tape options is not really possible anymore.

It isn't too expensive for my use case – per month, I retrieve about 500GB a month from Glacier Instant Retrieval to verify, which costs ~$15. Combined with other costs, my monthly bill is ~$50.

I used to use Backblaze B2, which had cheaper egress at the cost of slightly more expensive storage (I think ~$5/TB/mo, with free egress up to 3x all current storage?) So I paid $20. But at some point AWS opened a datacenter near me, and I couldn't ignore how much faster data transfers got.

use cloudflare's r2, no egress fees