Well, cobol is special of course. The more specialized you are... But for a generic c++, java or c# or web dev I would say you can't charge specialist money at all in the EU.
Well it's a negotiation. Those guys succeeded at asking for 2500, but you would start at a number they are guaranteed to say no to, and work your way down.
Like the going rate for a senior here is 900, and a good senior is 1200+. So your starting offer would be at least 1800, probably 2000s to round it up.
Which is the high end of your zone of possible agreement (900-1200) plus 50% for danger money, plus a few hundred to round it up to 2k.
Then you see what happens when you throw out the big number.
