180/year? That's ~150watt server. That's a very powerful NAS. You'll be paying $200 per month form a cloud provider for such performance. A performant home low power NAS can be build that will consume easily, 30-40W. It won't need to be upgraded for over a decade. Ideally, 5x HDDs with 5 year warranty. The only expense is rolling upgrades of HDDs as storage fills up.

Backup to cloud glacier storage is ~$1.20 per TiB-month

Cost is absolutely a factor. self-hosting can't even be touched. And, the that's just the start of the value proposition.