Xbox Video price discrepancy

I want to buy season 2 of the TV series Young Justice so I checked the WP Xbox Video app for the price. Looks good. About $25. So later I go to the Xbox Video app on Windows 8.1 and, what the heck, it costs $45. Don't your video purchases sync across operating systems and devices? Why is there this enormous price difference? If I bought it cheap on WP would I not be able to download it onto my Surface? Can anyone shed some light?

Did you select SD or HD? On WP it will always display the SD version since that is what is currently supported, you can select to switch to HD and purchase it in HD across your devices, but for now it will only play in SD on your phone until they upgrade the app.

Yes, the prices I mentioned were both the HD prices. There was a huge price increase for SD too.