When I was younger, I had a dream I went to a super market, and was immediately met with the newest product; the Discount Dreams. I could choose exactly what my dreams would be about for just $1.99. I chose one where I was flying. It ended in a fall and a pool of sweat at 3.30 am.

So, I wrote a story about a man who sold dreams. They were homemade dreams of course, and the finest at that. So, naturally, to this Merchant of Dreams, it felt like selling off a piece of himself with every sale.
He would sell the really good dreams to people who were very much in need of a GOOD night's sleep, he would give away the secondbest to the poor and homeless, for he was a man of a kind heart, and auction the rest of them to the highest bidder. The nightmares, however, were never purchased. Those were the only ones he ever got to dream himself.
Eventually they drove him mad, which influenced the dreams he so carefully crafted. They got skewed, off-colour, and very strange to say the least. No-one really knew what to make of them. So they returned them.

Unfortunally, running a "Used Dreams" shoppe is not very good for your economy.