I want to buy a Greyhound ticket for early November (and return-trip ticket for near the end of the month). I know what the price is if I buy the tickets now, but I may need to wait.

I know if I wait too long, the price is likely to go up, but Greyhound's ticket agent can't tell me exactly when.

The last time, I think it went up one week before departure. I don't plan to wait that long, but is it likely to go up incrementally some time before then?