Since drfuchs hasn't answered yet, here's a figure from 2011:
"Not up for chartering your own car? Then perhaps you'd like to take part in an arranged tour. There are several vendors that offer trips on private varnishes. For example, Palm Leaf LLC is offering a week-long trip by train from Los Angeles to New Orleans for Mardi Gras. While in New Orleans you can continue to use the train as your hotel, parked right in the middle of the action. The tariff? $2,995 per person for a single room, including meals while in motion."