Mobb Deep's huge success in the rap game came at the expense of the group's managers ... according to a massive lawsuit.
Buck 50 Productions says they managed the careers of Prodigy and Havoc from 2010 until Prodigy's death last summer -- and over that period the rappers racked up a serious tab. In the suit, Buck 50 says their team booked touring, recording and endorsement deals. They also paid advances to Mobb Deep ... for which Buck 50 was never reimbursed, they say.
Total cost for services rendered, according to the suit -- at least $500,000.
TMZ broke the story ... Prodigy died in June 2017, when he choked on an egg while hospitalized for sickle cell anemia.