Hi Ada - I am working on a report for a course I took on JewishGen on Immigration and have come across several good websites.  Do you have the manifests?  - they might have costs, ticket agency etc 
One deals with ships, their history, ports, immigration laws, etc and can be found at Historical Ephemera Collections 1880s - 1950s | GG Archives (gjenvick.com)

Another great article, that I think someone alluded to is Szajkowski, Z. (1977). Sufferings of Jewish Emigrants to America in Transit through Germany. Jewish Social Studies, 39(1/2), 105-116. Retrieved April 19, 2021, from http://www.jstor.org/stable/4466952

My pgm went on Holland America in 1917 and I was lucky to get in touch with someone who writes a blog for them and he was able to get in touch with him and he was able to read the manifest and noted that my gm and her 4 children paid "192 Dutch florins for the whole party of  which 75 florins was commission for the booking agency) 

I also wrote to the Museum of Polish History and a resource person there kindly directed me to the following map of the railway system  

Kolej_w_Kongresówce_1842-1918.png (1187×1403) (wikimedia.org)

Feel free to contact me privately for other notes I found which I am now trying to figure out where I got them 

Esther Levine Brill