Is there a cheap way to travel by train from London to Edinburgh?
Stephanie, The cheapest way that I know would be to take the short trip (~4.5 hours) on East Coast Rail from London King's Cross to Edinburgh Waverley. If you pre-purchase your ticket well in advance, considerable savings are possible. It's a very easy and pleasant trip. You may find it helpful to have a look at the excellent SEAT 61 website, as that has good information on how to buy tickets. Happy travels!
To get a discount fare on a high-speed daytime train, book ASAP (up to about 12 weeks in advance) at www.eastcoast.co.uk. To get a Bargain Berth on the Caledonian Sleeper, book ASAP (up to 12 weeks in advance). Discount fare tickets are for a specific departure date and time and are non-exchangeable and non-refundable. Be sure you can commit before booking.
If price is the key criteria, have you considered flying? It will probably be a bit longer journey door-to-door and certainly more hassle, but should be much cheaper if you book in advance with easyJet or similar low cost airlines. There is no practical cheap railway route, current prices to travel in March are £125, by aeroplane £35, plus any hold luggage fees.
Sorry to disagree with someone who lives in England, but Keith is wrong. While the standard 2nd class fare for London-Edinburgh is well over £100, advance discount fares can be as low as £17. I just checked the East Coast site and found fares as low as £28.90 for 14 March. (As of today booking is open through 15 March.) Bargain Berths on the Caledonian Sleeper start at £19.
Whoops, yes I forgot about checking on the operator's own site - so yes, ignore what I said and if you can get a cheap train ticket that is easier than flying.