Here are some interesting numbers who can help us figure out few things.
The GDP(PPP)per capita* of US for 2007 is 45.175$.
The GDP(PPP)per capita for EU(27 countries) is 28.213$.
The average price of a new released game in US is 60$.
For EU is about 65 euros ( 91$).
That means that the Average EU citizen pays 31$ more to purchase a new-released game, despite the fact that his purchasing power is from lower to substantially lower than the one of US citizen.
The real problem for xbox360, in order to become casual in EU, is not its hardware price (right now is appealing for many millions of EU consumers) but the software prices.
Also this is why piracy is so important for the commercial succes of a console in Europe.
*Gross domestic product based on purchasing-power-parity per capita
Using purchasing power parity is entirely useless in this context. In fact, consoles are more expensive in the emerging economies such as new EU member states (e.g. there's a thread on Wii price in Brazil, etc.). So using it is fairly useless, since they're not part of the basket determining PPP.
A more relevant metric would be the price of the console compared to median income (even better yet versus the median discretionary income) and even that would be somewhat sketchy given that the market is evenly distributed across age groups.
A more direct metric would be comparing the number of sold consoles and sold software. But that comparison is a bit marred by the fact that Europe / Asia are not well-defined categories in the yearly fiscal reports and vary from manufacturer to manufacturer. E.g. Nintendo reports Japan / The Americas and Other while Sony and MS have different categories.
But, it really is irrelevant how the EU compares to the US, what is of importance here, is how it compares to Japan. Frankly, the gap is far closer in that case.