Just to confirm. The only price that can be submitted by the developer/publisher to the MarketPlace is the $ price. Other currency prices are then set by Microsoft. What doesn't help is that they can't do upgrade discounts and so they offer a bundle whereby, if you own one part and then 'complete' your bundle by buying the other element, you pay the difference. Unfortunately, the logic can only knock 20% off the entire bundle, so owners of Part A, who then buy Part B, only get 10% off part B. It looks like MS has now reduced the bundle price to take this into account.