I'm surprised that a 30.06 is considered expensive. It got its start after the great war (WWII) when most of the GI's were allowed to return to the states with their rifles in tote (M1 Garand). I am guessing on the statistics, but I would be willing to bet that it is the most common deer rifle on the market.
As for overkill. I don't think there is such a thing when it comes to making an effective kill. A 12 GA shotgun and slug will make a much larger hole and do more damage. I would say that the 12 GA is more common, since many areas do not allow rifles for safety concerns.
I agree that big bucks do come out and do crazy things when the rut is on. It is a magical time of year when you see them running all over the woods. During the rut/post rut they typically won't come into a bait pile when love is on their mind. My statement was that the Big Boys won't come "IN" to a bait pile during the rut, not that they won't come out during the daytime. They will come out, but they aren't looking for some apples.
From those who much is given, much is expected