My $.02, only bring home a CBB if you see it eat frozen food actively while at the LFS.
Far too often CBBs are too stressed to eat anything prepared, and while in that state of being stressed they are typically not able to get the nutrition to survive the transition / acclimation process and they end up perishing. They need to be eating and putting on weight and they have a good chance and tend to be hardy fish if they make it more than a month or two. If not eating and putting on weight from the start, they are typically gonners (an no, our efforts to "rescue" them from the LFS will be in vain. We don't "rescue" dying fish from stores, we buy them leading the stores to order more and in the end killing more sensitive fish.)
Purchase with great caution. (I'm not in any way implying or accusing the OP of anything here, just taking in general about my own exp with these fish over the years. I've had two that I was able to keep for several years each, and in the end attribute inadequate feeding to their eventual demise. Currently I'm on my 3rd CBB and feeding it more aggressively and never missing a day, so far so good.)