Crookers is the conflation of Crack and Hookers. Two popular indulgences of the more affluent Scumbag (or Andrew). Common-all-garden Scumbags can normally only afford to indulge in Crack or Hookers but the Andrew can afford to juxtapose his pleasures with the Crooker.
Sean: Hi Andy, I hear you've just been paid. Finally getting that new jacket you've had your eye on?