May 14-21 in Scotland... My 2 adult children and I are traveling from Salisbury on Thursday (May 12) to London , spend a day or so and go to Scotland from there. Planning to go north to Edinburgh (east line), take in Inverness, Oban Stirling Glasgow and land back at Gatwick on the Sunday to head back to Canada.The pass is just over 1200 Canadian and I was thinking that depending on when we travel we can do it cheaper. Is it that much more expensive to buy tickets as we go? Next question is: Is it true that having an American Express card is as good as having an oyster card for traveling around London? I have a Master Card and Amercan Express for the the trip and am thinking that is the best way to pay for everything. Suggestions? thank you for the opportunity to ask questions!