$3k/month is the very top of the market.

Depends on 1) where the university is located (CoL), 2) if they went on strike recently to get paid enough to pay rent.

You can reliably assume that PhD wages must eventually converge to the rent of a studio apartment nearby + a little bit (which may or may not be enough to cover all other expenses. Going into debt is common.)

That amount is standard at EPFL and ETH, but I don't know about the USA.

I knew someone who got his PhD at EPFL. He earned almost triple what I did in the US.

ETHZ and EPFL are also top of the market in EU/UK.

Pedantic, but they are top of the market in neither since Switzerland is not in the EU, and definitely not in the UK.

But it is true that in Europe, Switzerland PhDs (and professors too) make most. Not just ETH/EPFL as well. UZH (Uni Zurich) has salaries of 50K CHF per year for PhD candidates (with increments every year) -- that's almost 60K USD by your fourth year. This is also true for other universities. And while Zürich is expensive, it is not _that_ expensive.

USA stipend is $25K to $30K annually

Lmao no