Wow, what a read. As a business salesman your main priority is to get bikes sold, not joke around with your customers. You don't know someone well enough to joke with them, and it could lead to having a customer walk out the door with a bad image, which in this case happened. No matter how good of a salesman this guy is, you just missed out on a sale, and plenty more from the way people view your shop now. Salesman are there to make the customer happy, get bikes off the floor, and to be sure that their experience with your company is top notch. Joking can be done after the fact. As far as out the door goes, when this is brought up that means they want to pay that price and that is it. They don't want all the extra amenities that are offered, and don't want to deal with tax or any of that. An easier way to deny that offer is to just say that you can't go that low. Common sense should tell you that.