We're getting there
As for the train, look again, please. It's an amazing journey. Even if you take the train one way and fly the other.
As I said previously they only release seats so many weeks in advance. At the moment they're booking up to July 22nd. Go to
www.gner.co.uk and you can set an alert so you get an e-mail when your dates go on sale.
The cheapest London-Edinburgh returns by train in July are £25, singles are £14. These fares will be the same for travel in October if you book 12 weeks out.
The taxes and charges alone on Easyjet from London-Edinburgh are £17, so you're out of pocket to start with even before you factor in the expense of getting to and from the airports. (Stations in the UK are bang in the middle of the cities).