Well, I downloaded the sample having reading this thread, so if it was sneaky marketing congrats it worked.

What I will say before anything else is that your price point was mental. If someone told you to do that they were wrong. Current conversion of $9.99 puts that at £7.67. I barely pay that for physical copies of established writers books. I wouldn't ever pay that for a unknown, new writer, especially in electronic format.

 Bad news: I can't finish your sample, I'm sorry, it's not good.

 Your description don't tie through. You want 'to paint the blackened sky with tens of thousands of different shades' but then call it 'red as blood'? How did you get there? It makes no sense, colours don't mix that way. 
Also your farmer's house has a ghost as the door opens by itself.
 Your farmer's wife can teleport as she was on the porch, then she's in the crater halfway across some 'grassland' of undetermined size, but since we're talking neighbouring farms wouldn't they be somewhat spread out perhaps? 
Your 'village' wasn't included in the farmers initial view of the land from his porch yet he could see it when it was destroyed. If you're using the initial view of the land to set the scene, missing out the village and the neighbours was egregious.
There's more but it's pointless to go on as I understand you aren't taking any of this on board. But for me as a reader, I didn't make it past what kindle calls 17% of the sample.

I don't mind if you go digging through my post history and drag out everything I've ever written and review it negatively btw,  I dabble with fanfiction and from my post history it's easy to find. I've got two underway that I've completely stalled on and you never know, it might jump start me again.
I have found the fanfic community are brilliant at encouraging and slating you by turns. Perhaps you might consider writing something short/medium weight and seeing if you can hone your craft in a live environment of readers, that way you won't have to wait to get feedback and can grow as you go, as it were.