Due to the upcoming Canada Post strike we are not currently shipping to PO Boxes. We ask you fill in a physical address only as we are currently going through couriers like Purolator, UPS & Canpar. Any orders with a PO Box will be held until the strike is over. For USA customers, we are currently shipping UPS. Some couriers are adding surge pricing. Due to ongoing market fluctuations and changes in the Canadian/US exchange rate, prices displayed on our website may not always reflect the most up-to-date pricing. For the most accurate and current information, please contact our sales team directly at parts@drmower.ca. We appreciate your understanding and apologize for any inconvenience this may cause. Thank you, DR Mower