Thanks for all the great information. I did not realize that it would be significantly cheaper to fly than train to Edinburgh. But I found deals for about half.
Interesting comparison of flights though.
EasyJet's web site had a price of 40 pounds per person round trip with taxes of 10 pounds for a total of 100 pounds for the both of us.
As pointed out, BMI had 7 pound each way fares. So, it was 14 pounds per person. However, theire taxes, fees etc. were 43 pounds per person for a total of 116 pounds for both of us.
Why the difference? The only thing that I could see would be the airports. The 10 pound taxes was from Gatwick and the 43 pound taxes was from Heathrow.
Thanks again for all the good advice!