public double cost() {
        if (model.isContent()) {
            if (requiresNodeReplacement()) return toHours(model.redistributionDuration()) * from.cost();
            return toHours(model.redistributionDuration()) * from.advertisedResources().cost() * nodesToRetire();
        }
        else {
            if (requiresNodeReplacement()) return toHours(model.nodeReplacementDuration()) * from.cost();
            return 0;
        }
    }
Returns the estimated total cost of this resource change (coming in addition to the "to" resource cost).
node-repository/src/main/java/com/yahoo/vespa/hosted/provision/autoscale/ResourceChange.java