Yes a euro is a euro, but its the same thing as something costing more in one area than another.

One possibility is tariffs on foreign items. The EU controls this so it may not be an issue.

There is always the differences in cost of goods sold - it might be printed in Germany and therefore cheaper to sell there. If they ship it to France it is more expensive.

Dont forget that the VAT is inclusive in Europe, meaning that the price you see on the product includes the tax ($X of which $Y is VAT) whereas in the US it is exclusive ($X plus $Y sales tax at the cash register). Doesnt explain the different here since the VAT in France is higher.

I am betting it is a tax that the French put on it. They have some odd ones...