I highly doubt that. A signature campaign participant would barely spend on something like this. They would rather create new account and wear the signature themselves after ranking up.
But if things don't look exactly as they are presented here?
Is it possible that the OP's is an alt account from a "dissatisfied" participant? The OP created another topic in the reputation board, to deepen this drama, everything seems to me like a passive attack on Royse's reputation.
How likely is it that someone will offer money for a signature space to an account that has been quite inactive until now?
A perfidious way to smear someone, while no one is exposed and there will be no consequences for future participation in campaigns.
Maybe I am just paranoid.