Contraband Dealers are Jobs In DarkRp that sell items to players. The items they sell are usually illegal, but Handguns are the exception. Some servers have custom Dealer Jobs that don't sell illegal items, like Car Dealers. Sometimes customers may steal from your store. It's not ideal to be a dealer when almost all the people on the server are criminals. They will most likely steal from you often, and run you out of business.
Drug dealers are Dealers who sell drugs. unlike the Gun Dealer, all that he sells is illegal, and its a very bad idea to build near the police as they will keep checking for illegal items. A trick is to put any illegal drugs or printers in your pocket. if you let them check normally, Its almost impossible they will find out you hid the illegal items in your pocket. unless they are very experienced and know this trick. if so, the cop will arrest you instantly. this is one of the best ways to stop cops from finding illegal items. however you can also put a kos area too, but you will need to have protection as well. be careful where you build, as it may be too close to police, or too far from spawn to be found. :D