I wouldn't doubt it, as my 2009 Worldwide Scott says $42.50 (used), and my 2012 Classic Specialized Scott says $500 used, but only $135 on cover. I agree with you that there is an extra zero involved. (I actually hope I am wrong, as I have a used copy of that stamp.)

There is a note in Scott's that "Forged or backdated cancellations are found frequently" on many of these issues.
By the way ... welcome to the Forum.