If you're a smart drug dealer (oxymoron I know) you wouldn't sell to them because it is a bad business decision. I assume you'd have no morals since selling drugs is bag no matter how you slice it... but drugs is ALL about return business. Someone who dies can't come back and buy more. Also, when word gets out that people die from the drugs you sell, you're going to lose other potential customers to boot.
IF you are someone who cares, you wouldn't be selling drugs.
I feel empathy for people who use and get addicted to drugs. They get to that point usually through depression or some other thing that is not entirely their fault and then get addicted and its a spiral from there. Easy to be sympathetic to a drug user... But dealers? Nope. No sympathy for that chosen profession.
As an aside, this is why I never liked the comedian/actor Tim Allen. Forget his politics, which rub many people wrong these days... dude was a drug seller in college. He served time. Early in his days as a comedian this came out, and to his credit he didn't run from it he owned up to it... but the thing is... He was in college, selling drugs, to fellow students... kids basically... he never took drugs himself... dealers who are smart don't get addicted because they know... so to be a dealer, you have to knowingly spread that evil to vulnerable people... and he stopped only because he got caught and put in jail.
I give him credit for turning his life around after that... and some movies he is in (GalaxyQuest comes to mind) are enjoyable and I overlook the flaws of the man for the performance... I separate that shit... but I don't like the man and never will because you don't decide to poison people with a clear mind and then become a better person later when you knew you were doing evil and were okay with it.
But I digress... Your drug dealer isn't going to want to support suicide-by-drugs because it is bad for his business. It's that simple. No morals involved.