[Jesse_Ray]

I reject the concept of self-plagiarism because I believe that people are entitled to use their own works as they see fit, provided that they have not transfered ownership or copyright. Even so, that is beside the point because the issue has nothing to do with plagiarism.

The issue has to do with the violation of the terms of the contract. If the publisher wanted something unoriginal, then they would make an explicit request to publish a previous work. (In other words, the publisher would say to the author, "We want to publish your previous work X. Can we negotiate a price?") When no such request is made and the publisher instead offers to pay the author to write something, it is implied that they want something original. That implicit request is part of the contractual agreement between the author and the publisher. When the author publishes something unoriginal and then takes money for the service of publishing something that is original, then the author has effectively stolen the money.