Get serious. Used Ruger Super Blackhawk .44 Magnums are common in my local gun stores for $425 to $450. If you need bear protection dump the 9mm and buy bear protection.
On the other hand, we are lucky to even get a glimpse of our local black bears. They are hunted so they are terrified of humans. If your local black bears have lost their fear of humans you can almost eliminate the likelihood of them being a problem by not leaving out garbage, pet and bird food or anything else for them to eat.
If you live where there are carnivores that might actually hunt and eat humans wait for another member to offer advise. I doubt any will recommend sticking with 9 mm.