It's always sunny in Philadelphia Season 4 Episode 2 : The Gang Solves the Gas Crisis
Charlie, Mac, and Dennis formulate a plan to take advantage of the rising gas prices. By purchasing excess amounts now, they can sell it in the future and profit. As usual, things don't go as planned. Dee is also out to make money when she learns that Bruce is going to give the family fortune to a Muslim cultural center. She and Frank try to stop him and get the cash for themselves.