Just my opinions.

If buying a new current issue rifle, you will mostly likely loose some off the new price if re-selling it reasonably quickly after purchasing it. Simple logic, if someone can buy the same rifle "new" themselves, why would they pay the same price for a used firearm?

Some factors can change that "logic" of course.

The waiting time for a new rifle. If it takes two years to get a 'brand new one' some guys don't want to wait and 'want it now!'

Also if you are selling it several years after buying it, has the prices of new ones gone up.

Vintage double rifles are a scarce commodity and it is simple, no more are being made, because they are vintage, as demand increases, supply is limited, their value appreciates.

Personally I'm not into the idea of buying a double rifle for a one off safari and then re-selling it. Much preferable to take a rifle the hunter is familiar with, rather than a rifle the client has rarely used and has little experience with.

The idea that a double rifle is only usable on a safari is erroneous though anyway. I use mine in Australia for buffalo, bulls, donkeys, goats, pigs and occasionally deer.

In North America I imagine they would go well on moose, deer and pigs.