Not sure the purpose of this, but someone may get something useful out of it.
About 3 months ago I went looking for a flight to Budapest for early December, returning 90 days later. The only flight I could find that was under $1200 that met my minimum requirements for lay overs and connections departed on Christmas eve and returned about mid-March. That flght was right at $900. I didnt like the dates so rather than buy it I set it up to notify me if the price changed (Google Flights). Well, its $1200 now. So I went looking again yesterday. Now there are a half dozen flights in early December, my preference, that are under $1000. They did not exist (at that price) 3 months ago.
I am pretty flexible. All I cared about was cost and roughly the first two weeks of December until some point 85 to 95 days later out of either of two airports and not through LHR or ChuckyD and 2 to 3.75 hour layovers. Max 2 stops, and will pay a $150 extra for one stop. All Basic Economy. Normally I dont like Lufthansa because of the carryon limitations, but this trip I will be checking a bag (there, but no return).
So, when to buy a ticket is anyone's guess.