The Salem travel trailers manufactred by Forest River in 2011 came in six different models ranging in length from 22 to 31 feet long.
You can use NADA Guides to find a blue book value by following these steps. We have used model [30CKSS] which is 31 feet long as an example using base pricing.
Go to [www.nadaguides.com]
Select = [RVS]
Select = [Travel Trailers/5th Wheels]
Select Manufacturer = [Forest River]
Select Year = 
Select Model = [30CKSS / Salem Series]
Enter Zip Code = 
Options = [Select]
[Get Base Pricing]
Suggested list price = $32790
Low retail = $10600
Average retail = $12750