I was looking up some flights for friends and family to travel ARN-PHL and PRG-PHL in end of august and end of october respectively. I found ARN-PHL return $415+tax (around 75$), PRG-PHL $485 + 75ish tax. Pretty good prices in my opinion! I researched the other way around for me to go there same time frame....PHL-ARN was $800ish+tax, PHL-PRG was $950ish+tax. What gives? Why such a huge difference? I can figure maybe 50-100$ different....but 400$? Its the same price to buy two tix europe-us, then us-europe. (and im sure i wasnt looking at one way prices). Is it just because of travel frequency of europeans vs us, or because they dont release fare sales so far in advance departing us?????