Question: what is the cheapest way to buy train tickets?
Answer: Get a Railcard or 16-17 Saver. With a Railcard you can get 1/3 off the price of train fare. ... 
Book Advanced Fares. If you want to journey by train in the future then booking your trip in advance could save you a lot of money. ... 
Buy a Season Pass. ... 
Use a Fare Finder. ... 
Avoid Booking Fees. ... 
Smart Ticketing.