I want to buy a Greyhound ticket for early November (and return 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?
Greyhound recently changed how they price tickets, so your experience in the past with pricing being based on time windows of x amount of days before departure is probably outdated.
Most tickets use a sophisticated yield-management model similar to airlines': prices change frequently based on things like demand and competitor pricing.
I work for bus a search portal, Busbud, where we partner with multiple bus companies including Greyhound and show them all in one place; we've noticed Greyhound matching prices from other companies like Megabus. So not only does the ticket agent not know when the price will change, but Greyhound isn't sure, they'll adjust the price to get as much money as they can while filling the bus as much as they can.
As part of this change Greyhound have also started charging much more for tickets bought at the station vs. bought online in most cases, so if you want the best price, book online.
You're still normally better off booking at least several weeks or days advance, but the bigger drivers of price going up will be how popular your travel day is (if you can find a day not many people want to travel you'll be rewarded with cheaper tickets) and if there aren't other bus companies competing on the route (if Greyhound has a monopoly they can charge a bit more, and probably need to, because the route is likely less busy or a competitor would step in).
This system also means Greyhound is now booking passengers onto specific buses, so you're no longer able to use a valid ticket for any bus, you need to show up to the time you booked. This has helped resolve issues around overcrowding on popular travel days: if you book a ticket, you're basically booking a specific seat.
I don't know about all countries where Greyhound operates, but what I saw about Canada (and I think it is the same in the US) there are a couple of times when the price increases. These are 21 days before, maybe 14 days before, 1 week before and 1 day before. These do not always hold, it depends on the origin and destination. In some cases it depends also on how many tickets are sold (from my assumptions: long-distance Toronto-Vancouver regularly went up half a dollar every couple days).
The important part is that so-called 21-day advance fare tickets can actually be used on any day between 21 days from purchase date until 6 months after. Since you apparently went to buy it in person, ask the teller to confirm this (conditions might have change since I bought mine or these conditions might be different in your country).
In the end if you know that you will travel for sure but do not know the exact dates, you can buy your ticket now for say November 1st and it would be valid any day between November 1st and around April 30th.
