«The Plagiarist From Rigel IV» by Evan Hunter

The Plagiarist From Rigel IV by Evan Hunter - Writing stories was hard work—unless Fred had a typewriter like "Reggie" that could write by itself! Nonsense? Fred agreed until he met— THE PLAGIARIST FROM RIGEL IV
I bought the typewriter in a pawn shop on Third Avenue.
The pawn shop proprietor was a balding old man with a walrus mustache.
"How much?" I asked him.
"Five dollars," he said casually.
I glanced at him skeptically. The machine was a Remington Noiseless, with italics, probably worth a little over a hundred new, and it couldn't have been more than a year or two old.
"How much?" I asked.
"Five dollars, is what I said. Five." He held up the fingers of his widespread hand. "Five. One-two-three…."
"What's wrong with it?" I asked suspiciously.
The old man shrugged. "Something has to be wrong with it? Listen, young man, don't look a gift horse in the mouth."
"How come it's so cheap?"
The old man sighed deeply. "You try to do a favor, you get all kinds of questions. Would you feel happier if I charged you fifty-five dollars?"
"I wouldn't pay fifty-five dollars. I haven't got that much money."
"Have you got five dollars? Can you pay that much?"
"Yes. But…."
"All right, take the machine. A case goes with it. Believe me, young man, this is a bargain."
"Five dollars?" I asked again.
"Five dollars. You want it? Yes or no? I got other things to do."
"I'll take it."
The old man smiled. "Good, you'll never regret it."
He slid the machine off the counter and put it into its case. He snapped the case shut then, locked it, and handed me the two keys.