I don't buy Advances very often any more, but the last few football seasons when I've been up the ECML, I have noticed that during the extended booking horizon:
- You didn't have the full range of retailers to choose from, with only the operators themselves and Trainline offering Advances, and
- In the case of LNER, prices for the dates of the relevant fixtures were higher than they would be subsequently, during the normal booking horizon.
In other words, prices can sometimes go down as well as up, it just doesn't tend to happen within the last few weeks before the date of travel. I believe
@yorkie has posted in the past about LNER and some of the dubious "book early for the best fare"-type marketing they may have put out, and whether it was accurate.
If you decide to wait and see if fares will go down, always consider what your options would be if Advance fares go up. Would you still want or need to travel on those dates? How much is the walk-up fare? What other options / modes of transport could you take?