Well done! Since you are already doing this, have you thought about signing the Cost of Knowledge [thecostofknowledge.com] petition if you haven't already done? In theory, this will prevent at least Elsevier editors from asking you to review in the first place and hopefully help establish more momentum for change.
In my experience with declining requests to review, I have commonly mentioned access and/or price as concerns for declining and have found some sympathy with various editors. If this becomes more commonplace, hopefully