Dear Professor X,
Thank you for the invitation to review for the Journal of X. I appreciate the work you do and have done for the X community.
That said, I have decided not to review for Elsevier journals unless the journal making the request is willing to convert one mutually agreed-upon article in the same journal to Gold Open Access status. If that condition can be met, I would be happy to review this paper, but if not, I’m afraid I must decline.
With best regards,
–Dan Gezelter
Thanks, I’ll borrow that proposal for the next review request I get from them.