Whoever is selling the "bonus story" story pamphlet for $115 is surely engaging in wishful thinking, and working strictly on their own. I VERY much doubt that Link gets a penny of that kind of re-sale. To my knowledge, he gave them away for FREE, when doing appearances to promote the book, and now, somebody thinks they can make a killing by re-selling it. This would also explain the re-seller having a signed copy -- he got Link to sign it at a personal appearance (for no charge, I imagine) and he glommed the free pamphlet there, and now seeks to exploit its "rarity". Hopefully there will be further editions of the book, that will include that story. It's a good story, but no more special than the others in the book.
In fairness, should add: I have no problem with someone selling the book/bonus combo at any price that someone wants to pay -- in fact, if that's a fair price then I am glad that the demand is there. But I wanted to correct the impression that Bill Link has anything to do with the pricing on what you saw, which as I said, seems unlikely although I haven't seen the ad.