That's how price of retail SHOULD be set, but here's the thing. Retailers are smart enough to know that they're not going to make much money if they sell their product in stores for $40, while the exact same product is sold online for $30. They'll simply refuse to carry the product at all, because the retailers are well aware that the sales from retail still remain a significant chunk of profits that the developers/publishers would be foolish to pass up. Other companies would be more than happy to take the shelf space.
That's why retailers can still insist on price parity between digital and retail copies. If retailers refuse to carry the title, then regional distributors have nowhere to distribute to. No regional distributors means no translations - even for digital versions, which means even less sales.
That's all right, I don't disagree with this. Afterall I don't preach cheaper digital sales. Why then not sell the game for the same ammount of money to the USA and the EU, both digital and physical? If you sell a game in the USA for 40$, sell it for 30 euros in Europe (all righ, 35 euros if you're adamant about consumers shouldering the entirety of the VAT) for both physical and digital copies.
Now don't tell me it has to do with localization. If some countries are used to localized games and publishers cater to them because they are big markets I see two fair solutions. Either price the game higher for these countries specifically or have everyone share the localization cost. Not only those who benefit from it and the other happless european countries who don't care about localization at all. Have the USA share the cost as well.
Games (almost) never get localized for my country. Everybody here plays the english version. Why should we share the same price with Germany (which is a much much wealthier country by the way) that gets localization? When there is a flat price then regional prosperity and localization don't come into the conversation at all but if we're talking about regional pricing, shouldn't these also be deciding factors?