Why are eshop games so expensive?

[Mnementh]

Devil_Survivor said:
The 3DS eshop has price drop sales every week so I always look for those to pick up games I want at cheaper prices. I'm not sure about the Wii U but, you think there would be some on there too.

I've bought ACIII for 10 Euro on eShop, so yes, WiiU has it too.