Im Gonna keep it short. Got any improvement add them in. 

The point; 

It'll give people more Roleplay options- They could open a 'Mobster Gun Club'

f you add money, it'll have to be taken from somewhere;

It could cost like $1,000,000 To set up the Traffcing business & 500k a month in expenses. 

So there aren't any thugs running guns.

Why Not ?

I guess it is all about what you sell and buy, name it whatever u want, Guns, Uranium...etc.

The Higher the Cash, The Higher the chance to get caught

Or human Trafficing

Who Would like to see a thug driving a truck load of Guns?

And exactly the higher the Higher! Plus if you get caught then say bye to the guns and your cash. 

so if i am understanding this correctly it would be similar to drug running, but if you get caught you lose the items/cash you were planning on using to purchase these weapons instead?

No If You Get Caught (Like a 15% Chance) After You bought the guns then the guns will get taken. Or There could be a bribe feature.