The illicit drug profits are more like $150 MILLION USD. They were estimated at $109 in 2010.
If you think for a minute the cartels are going to bend over, and compete in a free market you have no idea who you are dealing with.
Heroin is already legal in Rx format. The Russian Mafia is making bank in the Black Market Rx Opiates. Kids are dropping like flies in the NE.
Fentanyl is a bioweapon used in war, and to assassinate people, it is 100x more powerful than morphine, and all over the streets. Kids these days don’t stand a chance.
It's not a question of "competing" - their customers will simply leave them behind for the many advantages offered by legal sellers.