Sure you can make 10k a night for getting grease out of a dumpster...but the people that ultimately are willing to pay for the grease can’t be bothered to go to the restaurants that throw it out and offer to buy it...they find it cheaper and easier to work some crime network....uhm...yeah....
10K....what a crock. That would be about 10,000 gallons a night, and would require at least 2 full size tanker trucks with internal heaters to unload it.