Well, since there's only one legit attempt at answering the original question, I'm going to take a stab at it...
First off, where do you live? If you live in a state where medical marijuana is legalized, you should check around for a 'medicine store,' aka a legal pot shop. These stores are always looking for product.
If it's not legal, you're going to have to find a smaller time dealer. Like FDD said, 5lbs really ain't much, especially if you pull 5lbs every harvest (meaning every 2 months). Soooo... my advice is this: The best $$ to be made is in quarter pounds. Find two or three steady persons (I'll get to how to find them in a minute) that are at the qp level and sell them each a qp a week, or however often they need it. I'm not sure of prices where you are, but around here, 1,050$ is an awesome price for a dank qp and will sell super fast. With 2 or 3 people at about a qp a week and a harvest every two months, you'll be making some good timing.
Anywho, the hard part is actually finding those qp dealers. I'm sure you already have a pot dealer for your personal sacks, right? Ask him to hook an ounce. If he can, chances are he's around the qp level. And if he's already your pot dealer, you should be able to have some trust in him. Bang: runner #1.
I would now advize you to go out and try to find more new dealers who sell small sacks. Buy some from them time to time, regardless of whether you need it or not. Over the course of a month, just talk to them, blaze with them, get to know them. After awhile, you should have a pretty good opinion formulated. Ask if they can do the ounce thing, and if so, you have a good prospect.
A few tips to remeber:
-> Never deal out of your house
-> Buy a disposable cell phone; never use a phone tied to you
-> Never reveal the fact you grow
-> Do not front people
-> Make your drops quick and smooth
-> Use your intuition -- it goes a long way
Good luck.
-AR