No dispensary in any legal state is going to risk their licensing by allowing an entry level employee to provide product that they sell. Anyone that has gone through the licensing process and other requirements to provide marijuana to dispensaries is not going to be working an entry level job at a dispensary to begin with. Dispensaries already have access to all they need. There are over 150 licensed dispensary's within a ten mile radius of where I live. They have so much that they're almost giving it away. At any given time there are numerous promotions and discounts going on. In fact it's cheaper to just buy it when you take into account the cost in time and money to grow it. Which in my case is minimal because I use the KISS method. For some like me it's a hobby more than anything else.
It's tough to get started in any business and the cannabis industry has many more obstacles, potential pitfalls, and an unknown future. There is nothing stopping the feds from overnight deciding to enforce federal law "cannabis is a schedule 1 drug" and conduct raids across the country in legal states. Seizing assets and shutting businesses down. They show up with tow trucks ready to seize your vehicle. You might prevail in court and recover your assets but that could take years. In the meantime you're livelihood is put on hold. Nothing I'm putting my money into. I wish anyone the best if they decide to try and make a living off of cannabis. But for me I just don't see the reward/risk ratio I need to. Once you're all registered legally to do legitimate business your name is on a list that the feds have access to. That's a list I don't want to be on.
To the OP's original question. I posted the links to the California Bureau of Cannabis Control and California NORML. It's a much more complicated and expensive process than many people think. Click here to get it straight from the horse's mouth:
http://bcc.ca.gov/