The major issue when dealing with rail is scheduling of shipments. Yes, you can spend less to ship something across the country by rail, but it won't be to your door in 5-7 days. I might be there in a month, or two if it isn't a recurring shipment, or hadn't been scheduled in advance. It ships when they have an opening, and your product may sit on a rail siding for a while.

Do you want the good shipped there cheaply, or do you want it when you want it? Pick one.

I'm a fan of rail, but it isn't perfect. Neither is trucking.