If I lived in a drug infested neighborhood and saw three men approaching the house, I'd probably grab the gun. If I was startled by sudden hollering and banging on the door, same thing. If they kicked the door in, I'd start shooting. I wouldn't wait to find out what they wanted, even if they
said they were police. How would you know whether or not it was a ploy by the druggies to get you to let your guard down? It's a lose/lose situation.
Buying drugs there is a good reason to execute a search warrant, but do the raid at the time of the purchase; use a dog to find the rest of the stash.