Europe is really diverse in wealth and business climate. The wealth gap between different European nations is so large that the US probably seems like the pinnacle of equality. It's hard to talk about Europe in general in this sense. I've worked as a developer, where I made less than $600-800 a month. Although I was underpaid, but it probably wouldn't have been possible to make double that in my country. I think you might want to dial your question in slightly more than "Europe", perhaps "Western Europe".