I think this is a fine approach for the left to take, as long as the moral foundation is never sacrificed.
In other words, it should always be "we should do this because it's the right/moral/dignified thing to do (and if it saves money too, great)" rather than "we should do this because it saves money." Because what if new research comes out saying it _doesn't_ save money?
(See https://www.currentaffairs.org/2017/02/even-when-it-doesnt-s... for a more fleshed out version of this argument.)