Economical Car Transport for non Viper

[Red94Roadster]

My younger sister is moving home to Detroit from Los Angeles this month. She has a 2002 GMC Envoy that needs to be shipped home. The car has high mileage, so she's just looking for cheap transport. How much should it cost? Any recommendations on companies? I'm assuming that there are different levels of transport that would affect the cost...covered versus open, etc?

Thanks in advance.