听力原文：WA I'm interested in your packaging system, but it's so much more expensive than your competitors'. MB You're right. Our prices are definitely higher than systems from other brands in the same category, but every system we sell is supported with extensive on-site training, and the best long-term service plan in the industry. That's all included in the price I just gave you. WA What makes the service plan so superior? MB We'll send a technician out to your site every six months to calibrate the equipment and do routine maintenance. This alone should eliminate your need to make service calls. But if you ever DO need service, we'll send a technician out the same day, at no charge, for as long as you own the system. According to the man, why are his company's systems more expensive than others?