This being a complete momentum killer in a game where you'll come up against hard bosses that you want to fight over and over again to improve at fighting them but you can't because you need to go farm blood vials is absolutely awful. I never finished The Old Hunters because of it. It's not about them being easy to farm, it's about the momentum killing. Nobody wants to go farm blood vials for an hour after they were just a few hits away from killing Maria or one of the other difficult bosses because they didn't have a full stock anymore. (And you're handicapping yourself if you don't have a full stock which is not something every player wants to do)