I'm thinking about buying a double rifle and a 9.3x74R seems to be the cheapest. Anybody here ever used a double 9.3x74R on bison? Would a double rifle even be a good choice for bison? I know it's been used on elehants for over a hundred years but is a double rifle against charging African game different than hunting bison in America? Let me know because I have no idea.

Are you hunting Bison on a game ranch where you can walk up to them and shoot them or will you be hunting Buffalo in the Wild?  I ask because there's a big difference.  If on a game ranch you will more than likely be shooting under 100yds but if in the Wild ranges could be further.  The cartridge you listed is capable of taking Buffalo as it has been used in Africa on CPX3 game.  

I don't know how a double rifle would work in the particular application but having a double rifle would be cool.

Not sure what your budget is but I just looked on Gunbroker and they had a few other calibers for right around $5000

In the wild. I'm going to get a Winchester 70 in 375 H&H because it's a little more practical BUT I can't get that double rifle out of my head.

I've been looking at the Sabatti doubles on GunBroker.

The Winchester is certainly a little more practical and will pack a little more punch.  

I too dream of having a nice double rifle one day.