I am looking for the cost of a train ticket in the USA from like New York City to Los Angles for example in 1930. I found it on for an airplane ticket but not a train. Not sure if this Stack Exchange is the right place or not. I have done research online and can not seem to get an answer. The links always takes me to the Amtrak web site which is no good for me.
I was unable to find exactly what you're looking for, but Streamliner Memories has a collection of old timetables, some of which have information about fares.
From Chicago to Los Angeles in 1927, the fare would be between $12.75 and $84.00 depending on the class of service, though note that the price could be higher for some faster trains, and apparently discounts were available if you were willing to accept an upper berth.
I couldn't find any information about pricing for New York to Chicago trains at about that time, but it seems reasonable to assume it'd be less than the Chicago to Los Angeles leg, as the distance is less.