They wouldn't do it if there weren't idiots who don't do any research and pay ludicrous prices for things. You know what P. T. Barnum said: "There's a sucker born every minute."
Then let me apologize to you for reading it the wrong way. I'm sorry for that.
As an aside I'd never buy from a seller who I saw doing this. It may be common now days but seems wrong to me. I'd think he was trying to rip people off.