I agree: it's horrible! But, as numerous commenters have observed, the one featured in the submission is only available at retail in England and countries other than the U.S.; on eBay it's $175 + shipping/delivery/insurance.

This: "... I'd probably buy to replace my Oura ring if it had sleep tracking, heart rate monitor etc. rather than just step count."

If it had all those other features it would cost way more than the version offered!