Should I Purchase Train Tickets in Advance?

If you buy a couple of months in advance, you can frequently get tickets for less than 25% (or so) of what you'd pay last minute. This fixes your travel schedule around the prebought tickets and you risk losing the value of the ticket if your travel plans change. Be aware that in August any train ticket around the Edinburgh festival becomes more expensive than "normal." I am totally unaware of the 16-25 card.

When you get your ticket for St. Andrews you will need to buy a ticket from Edinburgh to Leuchars. Leuchars is the closest town to St. Andrews with a train station, from Leuchars you will need to take a taxi to St. Andrews. The train station is 4 miles from St. Andrews.

Buying tickets in advance usually saves money, at the cost of locking yourself into that schedule. If flexibility is more important, then buy once you're there. You can save money by buying tickets a day or two ahead of travel. You can do that at the stations. As mentioned, if you will be in or around Edinburgh during the dates of the Festival there, be prepared for crowds and boosted prices. Hotels and b&b's will be very booked. If you buy tickets in advance and are offered the chance to make seat reservations, there's no harm in doing that. Most times it is not necessary, but there are occasions on which trains are full.

I'm assuming you're talking about one flavor of the Travelcard with the reference to the 16-25 card. We are buying ours in London but, alas, are not 16-25.

The 16-25 railcard is the new(ish) name for the previously Young Person's Railcard, is valid 12 months, costs £28, and gives about a third off most National Rail tickets. There are time and minimum fare requirements before 10 am M-F except July and August. They are only available, as the name hints, to youngens 16 to 25 years old.

Thanks for all the advice, I think I'm going to purchase the longer journey and more definite tickets before I leave and save the shorter trips for when I get there. I did find how challenging it is to get a room during the festival, and how the prices go up (double in most cases!), but I booked a room in a hostel from the GB guidebook. Luckily I am in the 16-25 age group, (19) so I will be able to purchase that particular railpass upon arrival! Thanks for all the help!
Annaliese

I would definitely purchase tickets in advance and reserve seats for the longer journies. I have travelled often from London to Perth in Scotland and there has been standing room only.

Do not forget the Bus. National Express is having a 9Pound sale at the moment.