Two times you have done this to me. I have gone out, purchased a 1500 point card for $25. Only to get back home and be disappointed that Dragonborn (along with Dawnguard when I got it) were 1600. I don't know what stuff you're pulling.
Cards in Australia are $25 for 1500 and $50 for 3000. That's just some cheap marketing scam seeing as how mostly all important things on the store, like this, are 1600 points.
I sincerely hate you MS. From an extremely disappointed Elder Scrolls fan.