Cartman and the gang head to KFC after soccer practice only to find out it’s been converted into a new medicinal marijuana shop. Cartman convinces his mom to drive him to a nearby town for KFC, but that show has closed as well. Cartman learns that Colorado has recently passed a bill that bans fast food in low-income areas, but it turns out KFCs were only built in low-income cities, so there are effectively no more KFCs in the state. The state government has essentially set a price ceiling for KFC in low-income areas at zero dollars. One of the predictable side effects of these price controls is a black market for the item. Items with price ceilings also tend to have inefficiently low quality. The banning of fast food causes Cartman to enter the black market to feed his KFC addiction. In later scenes, Cartman is upset because he catches a dealer cutting the KFC gravy with Boston Market gravy. When the dealer suggests he can take the gravy back, Cartman notes that no one wants fried chicken without gravy, implying the two items are complements.
Thanks to Thomas Jandora for the clip reference