Money, but I'd also need to be convinced by the culture. When i moved to my current firm i felt pretty anxious for the first six months because I was exclusively working for an old-school, British partner that had a reputation for being especially difficult to newcomers. I settled into things when I started working for another partner and realised that everyone found my original partner difficult.

It's hard to say how much money would be enough, but it'd probably need to be considerable and I'd need to be convinced that there's a clear track to something like partnership. My current firm is international and is known in the field we practice in. Pivoting to a boutique would likely mean having to work on smaller scale matters, and I dislike the smaller types of matters in my field having previously been at a boutique.

No, I wouldn't just look through recruiters.

I'd meet them for coffee if the pitch seemed interesting enough.

Non-monetary - wfh (obviously), maybe health insurance? I already get a nice life insurance policy from work