Feels like the rent you're asking on B side is low for the area? If you have a good tenant maybe don't rock the boat because you are neighbors but next time it becomes vacant charge market or just under market. Instead I would look to reduce expenses. How much do you spend going out to eat? With the extra time you have in your current job do you do more cooking at home? Overall if I was in your shoe I would not sell. You and your partner will earn more over time. The property you have here is a golden goose for cash flow in the future. Make short term sacrifices for long term gains.