Or German, for that matter. Both have major (industrial) vacations in August.
We Swedes tend to have ours in July. Which is maybe a bit backwards for some, since I for one tend to have more time for FLOSS during my vacation.
There is no catch to this difference in price. The seller has evidently found out that software can be sold at a higher price in Europe. That market "can take it", so to speak.
Simply compare it to the Big Mac index — i.e. what's the difference in price between different regions? I wouldn't be too surprised to see the two curves (big-mac & software) to line up just fine.
Of course, the Big Mac index does not take work for everything. E.g., the price of petrol/gasoline has risen quite dramatically across the globe, but some places (read: Sweden) have quite high penalty taxes that further increase this. It was almost $2 per ISO liter before the summer... but you know, we can take it.
Your fault -- core dumped