I noticed this yesterday.
On the US store Monopoly and Fifa 11 are both half price right now and full price in the UK.
They were both on sale at 59 pence earlier this week.
Are you sure that wasn't the iPhone versions? I've been watching the iPad versions like a hawk!
http://appshopper.com/games/fifa-11-by-ea-sports
http://appshopper.com/games/monopoly
I really fail to see the "problem". They are different stores serving different economies. They could be making money a lot more in the US store that they can afford to pull the price down as opposed to the UK one. Just cause an item is on sale on amazon.com doesn't mean it "should" be on sale in amazon.de.