The second reason why prices are usually cheaper in the EU and France is the VAT tax refund system that is established in countries of the European Union.
In short, you will be refunded the VAT (i.e. sales tax, which is already included in the price) on products over a certain amount, which in the end makes the product cheaper overall.
France's current VAT refund rate is 12%, according to Upon.io. This means that you'll get an additional €228 ($222) off that Pochette Metis bag that we used as an example.