score:4
CountryLink (or as it's now known, NSW TrainLink) prices are fixed, and do not vary as you get closer to the travel date, however they do vary depending on the time of year - specifically around times of School Holidays. Technically the prices are cheaper during off-season periods, rather than the other way around!
You can find details of the dates for the peak/shoulder/off-peak date ranges on their websites under Seasonal Fares.
In addition to these discounts, they also sell tickets called "Economy Saver" which are discounted even further. These are normally only available during off-peak periods, have limited numbers available, and generally must be purchased in advance.
Upvote:3
NSW XPT prices appear to increase in school holidays (I thought they finished a week earlier than they did when discarding them as a reason). Checking past the actual dates of NSW school holidays shows it dropping back to $34, so it appears to be a high/low season cut-off where school holidays are high season.