Fuel & CG rates are usually quoted inclusive of taxes. The USD is only 75-80 cents to the CDN $ depending on exchange rate of the day. The last few years have been a great time for USD people to travel to Canada. I was very surprised at how few US tagged RVs I saw on Newfoundland in 2016 & how few again in Ontario last year. Canada is a beautiful place with wonderful people. Everyone is born with a Tim Hortons cup permanently in one hand.
Some things are more. Fuel being one of them however you go into Canada with tanks full & try to come out near empty. It is a game to play. Grocery stores are different. You might need a looney to use a cart. They are more concerned about the enviroment. Take your own bags into the store. Some charge for packing bags.