Recently my series 3 has been awfully buggy, Fixes/ recommendations on upgrade?

[MacAttackKev]

For the past couple of months, I've had to reset my apple watch to upgrade to the new os or to even pair it to my iPhone 11 pro max. Today it wouldn't detect my iPhone so I ran another reset, but now it fails to pair at all (It tries to pair then unpairs) and is now stuck on the setup screen. I Tried pairing and restoring a backup as well as setting it up as a new watch, both with no luck. I also did multiple resets via the crown to try again, but it still failed.
Does anyone have any ideas?

I have been meaning to upgrade anyway, but I was still hoping to get at least another year with it since it's still in good shape. Oh well.
I also don't keep up with the watch series as much as I do with the macs and iPhones so I'm not too familiar with the recent upgrades. Which series do you think would give me the best upgrade-to-cost ratio? I also don't mind buying used if that helps.

 

[ajcgn]

I don’t know what your needs are, but I bought a new series 5 a few months ago from a surplus store at 35% of the price of a new series 8 and love it. It doesn’t have a warranty, but it worked perfectly out of the unopened box and the battery health is still at 100%.
Wikipedia has a listing of all the watches and the upgrades going from one series to the next. According to wiki, vs the 3, my 5 has the 44mm display vs 42, 32g of storage vs 16 or 8, can measure ECG and has the always on display among other differences.
While a series 8 obviously has more features/improvements, the AW 5 is my first AW and I couldn’t justify the price to myself of a new series 8. So far so good as it does everything I need.
Hopefully other’s can share their experiences.