I'm comfortable waiting and I do wait and I attend a lot of events, but admittedly very rarely BYU games, so I can't really speak of the very unique dynamics and economics around those. A lot of people are, understandably, very uncomfortable planning a big weekend or night without tickets in hand. I am fine with that calculated risk.
Nearly all events (concerts, games, etc.) I do attend I buy tickets day-of and I generally pay well below what I would have paid a week before for the same seats. That said, I have been burned more than once.
Again, speaking generally, not about BYU games: Stubhub carries much the same inventory as its competitors, EXCEPT often Ticketmaster verified resale does have unique inventory. I end up with TickPick, StubHub, and Ticketmaster sites or apps all up at once at the moment of decision.