What is the average weight of an unladen swallow? Holy cow! Too many numbers! Leave the #’s and google in the lab, this is the real world when it comes to de-icing a lot. There are to many variables that come into play. And $180 a ton? Are you serious? This poor guy has been losing money, no wonder he’s been charging you for 2 ton more often... he’s trying to make up some of the money he’s been losing. I feel for him but he obviously did not do his research to know how and what to charge, he sounds very confused. I would have to guess in TO he’s paying somewhere around $120/ton just for the product! Maybe more and that doesn’t include GST, ha ha. That = losing money. He’ll be out of business soon...However, it should NOT take 2 ton of salt to de-ice 14,000 sqft! Salting is a maintenance routine so there should never be heavy ice build up or a heavy snowpack on the lot. Even if there was, 1 ton would be more than enough to melt the worst of conditions on 14,000 sqft. You are by no means getting hosed you hoser, hopefully he has been using a lot less than what he thought he needed. Next time he applies salt take notice if there is a lot of salt left on the parking lot after everything melts, that’s a good indication he’s using too much or way too much( not good for the environment).I would advise to have a reputable, honest contractor give you an estimate. And...Go Leafs! The Sabers are horrible...again.