A lot of guys who make/sell drugs will give you a bulk order discount.
The guys I used to buy from would even turn on a reactor especially for me if I ordered enough.
You just then don't pass the saving on to your corpies when you sell them the drugs (which is fair, organising a drug delivery takes time, doesn't it?).
We rarely give bulk discount but we do deliver anywhere in the game for free.
The gas miners mine the gas (the raw material) and sell it to the chemists (usually corp directors with tower access, extremely limited) at a good fair price so the miners make great money.
The chemists produce the drugs in the towers and sell them at a lower dealer only price to our dealers.
The dealers then sell the drugs to their contacts and customers.
Each stage makes a profit. But each stage isnt responsible for the other (necessarily) If a gas miner dies with his gas, thats his loss, if a dealer dies on a drug run. thats his personal loss.
That said if you're capable you can do multiple stages, most of the dealers also mine a bit of gas if we have something in particularly high demand. Over christmas everyone had to do a lot of gas mining as demand was insane.
Unfortunately for a chemist to make drugs he requires full tower access which includes corp wallet access and access to the entire drug stock. (we're talking tripple digit billions) so its something only really 2-3 guys are trusted to do.
We offer competative prices and keep a very neutral relationship with people where possible.
The smuggling is quite fun. But extremely scarey

huge deals are extremely hard to skill for as if you're moving 4b+ though nasty nullsec zones you have to start looking into BOPS and cov cynos and such.
For the most part we stay quiet and under the radar. and we dont stay in one place too long. so we go by unnoticed.
Join channel "narcotics" if you're interested in some boosters
PS, we're lucky enough to be able to keep our reactors running full tilt even when we're low on buyers. Usually in those times gas is cheaper and we can stockpile drugs in the event of a random huge order or a nice big demand spike. lulls in eve dont effect our production. Which is nice.