So, this raises something.
Presumably, the money will be "equivalent local currency". But then, for Valve to not look at cost-of-living and local salaries would be a very un-Valve thing to do. It's like pricing your game at $60/£60/60 Euros and then pushing that into Russian Ruble, Chinese RMB, etc. Makes no sense.
So, I would hope that Valve actually tailor costs to the specific country of the developer/publisher. And this may be why they are saying they're going to ask for tax info and "bank account" type stuff - so they have legal documentation of where you're based, and then ask for the required amount in local currency, taking into account how much people earn. This will prevent people saying "Ah, yeah, I'm based in Russia, so I'll pay the small amount of Ruble fees" even though they have UK tax info.