The buying of seats (or the "clickfest" as it"s become fondly known) for the National events is via the APAT website.
What generally happens is that we all sit at our PCs about 5 mins before the time the seats go on sale and frantically click "reload" every 5 seconds until the payment link appears.
Once it appears, it"s then a typing speed test to get your credit card details into the system before all the seats have gone, which is usually between 2 and 5 minutes.
If you"re successful in buying your seat, then well done, you"ll have a great time.