Monopoly differential pricing based on different costs for different consumer groups can increase total welfare compared to uniform pricing. Even if total output decreases or its distribution among groups worsens, at least one of these changes must be beneficial under certain conditions. Consumer welfare also rises, as price variation without an upward bias in average price can improve consumer welfare, even if output decreases. This contrasts with third-degree price discrimination literature and shows that varying prices can benefit consumers when demand elasticities and costs differ.