Buy thugs periodically to keep a healthy ratio of whore to thugs. Don't be an obvious target. Dumber This is how it works. Pistols get one shot off, shotguns two, Tek-9s nine, AKs 30. But this is not expressed in a linear sense of value within the game.
Shotguns cost nine times as much as pistols.
Tek-9s cost a little less than three times what shotguns cost, and provide 4.5 times the firepower. AKs cost three times what Tek-9s cost, and provide more then three times the firepower. Buy as many AKs as you can. Early on in the game, have a couple of AKs, but mainly buy pistols until you can afford the best. Tek-9s and shotguns are basically not worth buying.