What Is A Fair Price

The conundrum;  what is a fair and competitive price for ebooks/short stories, both fiction and non-fiction?The pay-off;  have you noticed there has been a renaissance, the classic 'rebirth,' of the art medium called the short-story lately?  And have you noticed the unbelievable surge in sales for ebook readers of all makes and models?  I mean this last point hasn't seen just a modest rise in sales from month to month, or year to year.  It literately has been explosive!  Shocking!  Millions are clamoring to buy an e-reader . . . and by extension . . . millions are eager to buy something to fill them up with and read!
The enjoyable past time of reading something . . . anything . . . has suddenly become both luxurious, and affordable, again.  Because of new technology, and thus more affordable reading material to the masses, the hoary old man called the short-story suddenly has been infused with new blood. 
And let met tell you, pilgrim . . . the number of talented short story writers out there waiting to be discovered is staggering to behold!
So back to the original question.  What is a fair and competitive price for a short story?  A novel?  Even a textbook.  A seminal question if you ask me.  The reduction in the cost of buying something to read has fueled this renaissance in fiction.  Especially the short story.  On the other hand--make the price of buying something to read so insignificant and how does a publisher, and the writer, make a living?
Here's the perfect example;  above is my Call Me Smitty; Fairwell, Brother .   Number eight in the Call Me Smitty series.  Like the other seven installments, this one was/is priced at ninety-nine cents.  Three stories for ninety-nine cents.  If you ask me, one hell of a buy!  But (and if I have enough fingers and toes to count on) I figure out of the ninety-nine cents, and after publisher and ebook carrier get their cut of the deal,  maybe . . . maybe I might get between twenty-five and thirty-five cents per.  And I'm not complaining, mind you!  Royalty payments for ebook writers are far higher and more lucrative that royalty payments given out to those who write in the traditional medium.  So I'm not complaining.However, you can see rather clearly, for me to earn a living selling short stories I'm gonna have to write a shit-pot load of short stories, or I've got to figure out a way to sell billions of'em per year.
Cut to the newest release in the series; Call Me Smitty; First Kill.   (see right hand column, first selection) After the momentary sales effort goes off for this puppy is gonna be sold at $2.99.  And that's okay by me.  I think it should be.  The three stories in this one makes the totality of the product far larger in word/page count than whats normally found in the first eight.
But is this really over pricing the product?  Or under valuing the product?  That's the puzzler.  On one hand you don't want to as crazy as traditional publisher have done in the last 30 years in jacking up the price of a hardback book right out of the roof.  On the other hand is the desire for, hell . . . people to make a living!
So what's the fair price for the material offered?
I suspect the prices are going to begin inching upward.  There will be all kinds of reasons why it'll happen.  There is no such thing as entropy.  All things change.  Even empty space isn't truly empty.  Which means, I guess, the best we can do is hope the rise in price doesn't take us into a lunar orbit.
A low earth orbit will be just fine.