Buying a mail order Dragoon or Walker will be less expensive and they will do the job. However, you'll need a dedicated holster as carrying one of those hand cannons, well, it won't fit in your pocket and you'll very soon not like sticking it in your belt.
You know something the Leather holster I got at Lowes to carry my electric screwdriver while putting up fence panels fits a Colt walker pretty good. I think I paid $8 for it.
The Walker or Dragoon will do for Black Bear but a large Brown Bear is a tough customer, even a .357 would be too light for certainity.
Black Bear, even the biggest , are unlikely to attack an armed man. The Black Bear attacks I've heard of involved sleeping campers, usually the Bear being drawn by the odor of Menstrual blood which made the Bear think the Female camper was already dead or dying.
Twice Black Bear have made a run at me, both times while I was trying to get a photo of them feeding on refuse. Once because a dumb kid followed me into the brush and threw a watermelon rind that hit the Bear (largests Blackie I've seen, well over three hundred pounds) in the face and the Bear apparently thought I threw it.
The other time a small adult Bear had his head and shoulders in a trash can and when he looked up and saw me it startled him.
Their tempers are short but they cool down almost instantly unless battle is joined immediately. If battle is joined with a single foe they fight like lions till they die, but if escape presents itself they will usually flee a dog pack.
Black bear sucumb quickly to even pocket pistol calibers if you center the chest. A friend's Granpa killed dozens with one shot each from a .32 S&W.
The Granpa was a career LEO though, an expert marksman, and cold as the snow.
The Cherokee thought is was dishonorable to use any weapon other than a club to kill Black Bear, and would formally apologize to the Bear before killing it, around here we call the Black Bear a Cow with Claws.