I"m writing on behalf of my sister and brother-in-law who have been quoted a ticket from London to Sheffield via train by a travel agent in Australia as being 300 pounds each person each way!!! I find this very hard to believe! Can anyone help with train companies we should look at? Is their one company that runs all trains? I'm assuming this would be a busy route with trains leaving every day and quite often - they will be staying in central London (not booked yet - any suggestions close to whichever station the train leaves from would be greatly appreciated). Thanks in anticipation.