I checked to see and I found something interesting - that begs another question ...
The SM and SS both run from Savannah, Ga to Kissimmee, Fl.
There is a $20 price difference between the two if riding in a Roomette. Also, the SM stops in Jesup, Ga while the SS does not make that stop - other than that they make all the other same stops and travel the same path.
They also travel the same path between Rocky Mount, NC and New York Penn. On this route, the only difference seems to be that the SM stops in Fredricksburg, VA and the SS does not. However, this time, not only is there a difference in the price between the two trains, there is a price difference in the direction
Again, I used the price if riding in a Roomette.
The SM is the same price in each direction ... but the SS is $28 more when heading north than it is when heading south. That makes the cost difference between the two trains $60 heading north and $88 heading south.
There does seem to be more than a $7 difference ... but
why does the upper segment of the SS cost $28 more in one direction than it does in the other while the lower segment of the SS is the same?