Two ferry services to Mackinac Island

Check out this link (https://www.mackinacisland.org/stay/getting-here/) which highlights different methods of transportation to/on Mackinac Island. For those who don't know, Mackinac Island is a little island between Michigan's two peninsulas where the only cars allowed are emergency vehicles. It's pretty neat if you have a spare weekend and want to visit an interesting place. Anyway, check out the two ferry services that take you from the "mainland" to Mackinac. Notice anything about the pricing of the services?