Very interesting difference between the U.S. and Canada when it comes to the cost and the reason why.
We have used the toll roads in Texas around Houston and in Florida around Orlando with minimal charges. The highest cost was around $8.00 and you have to pull into a toll booth with an attendant.
So in Toronto we took the 407ETR to avoid heavy traffic and learned the heavy cost of not having a toll booth attendant! Let's employ more people Canada!!!
It is an Automatic $50.00 for the video charge for a heavy vehicle RV or commercial. The only way to avoid this charge is to sign up for a transponder yearly. The FAQ's state you need to use it a minimum of 4 times to make it economically feasible. Oh and that $50 is not your toll fee that is additional. Ours was $24 running from the on ramp in Milton westbound to the off ramp for Hwy 400. So it's a matter of easier driving at a cost of $75 one way.... Something to know when driving around Toronto:)
Your other option is to take 401 Hwy which is traffic jammed most every day or find a hwy that meanders thru the countryside. The downside would be your time and diesel fuel sitting in traffic. Roads in the atlas don't tell you the dollars but sometimes it's worth your sanity!