It is a risky business all together where I'm at so I may be a little biassed. With that said in my circles we all have similar things at risk and never sell to a new face. If your willing to take some extra risk and work 100% minus grow cost obviusly, but that make for great margins.
yer if your willing to put in the work u will get the rewards and if your only dealing with people u know ur minimising the risk. however dealing with 1-2 people is always going to be safer than dealing with 20-30. but thats why u make more money dealing with more people.
i think it all comes down to how much the grower wants to work and profit he wants to make, some arecontent with making a decent profit and let others make some cash of it too. while others really want to optimize there grow and squeeze every last penny out of it