It's possible the authors signed a contract that allowed commercial use by Wiley that somehow extends to Elsevier. (That seems a bit odd since they are competit

It's possible the authors signed a contract that allowed commercial use by Wiley that somehow extends to Elsevier. (That seems a bit odd since they are competitors, but it's not outside the realm of possibility.) Even if that's the case and it's technically legal, it seems disingenuous to sell the article, since the authors presumably paid a fee to make it freely available to everyone.