I am about 40% into the game, and I use cheat codes. Right now, I play as Trevor.  Near my safehouse, I have a circuit of robbing the gas station near me, then going to the barber shop, tattoo parlor, and nearby gunshop. Killing each of those with explosives gets me 100-300 USD each time.  In a circuit, I keep getting $500 or so USD quickly, reliably. Any other tips to make cash?  Taxi cab drivers, robbing stores, etc.?