Does anyone know how it compares to restic or duplicate?

I use restic. Restic offers everything advertised on the tarsnap website (deduplicated snapshots, e2e encryption). I pay $6 per terabyte per month using backblaze's cloud object storage. Wasabi offers 1TB at $7/mo. S3 costs $26/mo, but glacier is only $3.6/mo.

Storing one terabyte of data in tarsnap costs $250 per month.

Basically the same service, but much more expensive.