If you are looking for something good that can light up and charge the Busch and Müller Luxos U is a great option. I think it is now 90 lux which is very bright and being a German brand it is of high quality with a good beam pattern. It isn't a cheap light but good lights generally aren't cheap and this one also has USB charging.

Peter White sells it and is super knowledgeable about dynamos and all of that, I learned a lot from him:
https://www.peterwhitecycles.com/b&m-hl.php

I wouldn't recommend low lumen or lux lights the idea is being seen and also allowing you to see so something nice and bright with a good beam pattern is always important. My two current dynamo set ups weren't super cheap but they are really nice and I probably wouldn't change a thing unless redoing the set up on my touring bike (because running the Sinewave Reactor wires was a pain) but for that I would just go to the Luxos U or Sinewave Beacon (which is MUSA)

Dynamos are awesome but the cheap stuff is not a ton different than the cheaper battery and USB lights aside from not having to charge or replace batteries and sometimes being rather large and not as sexy.