In my mind, I always classify DGDG's (Dangerous Game Double Guns) as Offensive or Defensive.
Offensive DGDG's are used to take the first shot on unwounded game (usually at the heart/lung area with a soft point) then maybe a quick follow-up, often times with a solid, at somewhere else on the animal to break the animal down and keep it in sight while the first shot does its job.
Defensive DGDG's are carried by PH's and used to save lives at close range, on adrenaline-fuel animals usually running directly at someone. For Defensive DGDG's redundancy and reliability are king.
If we're honest with ourselves, a quality bolt gun is just about the field equivalent to an offensive DGDG, maybe even preferred because the wider range of optic options on a bolt and the familiarity to the gun by the user.
If I ever get a DGDG the financial hurdle will not be the cost of the gun, (call it $10k) but the frequency that I'd be able to use it. I figure about $20k minimum per animal considering flights, day-fees, etc. that will drive the decision.
That being said, my interest in hunting buffalo is greater than zero but my interest in killing a buffalo with something other than a double rifle is exactly zero...
When I started shopping for a first double rifle, I started looking at large caliber side-by-side guns. Thank goodness my pragmatic nature kicked in and I realized that it wasn't the first $10k that was the limiter, it was the $20k times N that was the problem. I'm an American that got to hunt 49 days in 2021 with a double rifle without every having to spend a dime on flights, day fees or trophy fees. The $/day or $/animal is something well within my pragmatic budget.