I have been using a Pebble Time Steel for years even after their acquisition by Garmin Someone corrected me it was FitBit not Garmin thanks to Rebble, a modded firmware that gives it new life, but I would like a smartwatch that can track my heart rate.
I don't mind using an older device especially if it means a cheaper price. A bonus for me would be if it still had some kind of community around it or a custom firmware like Pebble watches do.
I found an original Moto 360 with a functional battery for about $30 but I am not sure if due its age its functionality would be greatly limited.
Edit: It seems like Garmin and FitBit might be worth looking at. But I wouldn't know what devices to look at or if there have been any major improvements with recent revisions.
Edit: Just an update I bought a Garmin VivoActive 3 used and locally. It seems to have some solid build quality but appears to have significantly less apps and features compared to my Pebble. The heart rate sensor seems to work alright though. I am a dork for metrics so I feel like that should make up for it.
i'm using a miband 5 for years now and still works fine.
it was only ~35€ when it was new.
I have a Miband 6 and it's pretty nice. The advantage over bigger smart watches is the battery lasts like 2 weeks more per charge.