Does anyone know of an api/dataset where I can see the average bus/train fare between two locations?

Indian railways? I once built it for the Indian railways at the company I used to work with, but they had some customizations in terms of fares and the API is not open to everyone now. If you can do some manual work and serve it over an API, here is some data I found http://www.indianrailways.gov.in/railwayboard/uploads/directorate/coaching/TAG_2017-18/Fares.pdf