After having heard a Pico lately, I could live with it as a DAC/amp if things got desperate. As far as cans go, I'd want to do a bit of research to see what has good synergy with the Pico. The Yuin PK1s I tried did offer exceptional value for the money tho so these could be considered on the cheap.
This thread is just a reminder of $$$ vs diminishing returns, so I'm trying not to think about it too much.

I think finding something with a musical bias would be the key, so I can enjoy it without worrying too much about whether it's getting everything right.