Got my windows phone 8 dev fees refund

I received yesterday the 91% refund of my windows phone 8 dev fees.
While I was afraid to receive it in 2013, Microsoft was not so slow on this one.
I still don't understand why I didn't pay 8$ only, without the need for a refund. Perhaps to select who can register..?
Or to avoid to handle different price for different people ?

Anyway, it's now time to make my vmware image of Windows 8.
I hope VS and the emulator will support it.