you contradict yourself as well as you can quickest=cheapest

I didn't contradict myself at all. Speed and price are two separate concerns. One does not imply the other.

Water was by far the cheapest way to get goods to market until railroads came along.

No it was not and that just defies all business logic. Do you really believe that a freight forwarder using steam ships that could guarantee your delivery in matter of days vs a matter of weeks via a service that employed horses didn't charge a premium for that service?

What would be the point of that?

Why do you think towns and cities are usually located adjacent to navigable waterways and natural harbors, going back thousands of years?

Take a trip down the Rhein river some day. There's a medieval castle at every opportunity next to the river. They were built to extract tax from the river traffic. The Rhein was the highway through Germany until railroads.