Michigan here
the licence cost is negligible compared to the cost of growing,
-if you are going to grow outdoors it still needs to be locked up in a green house
-Outdoor plants produce a lot of volume which can be an issue ( you are allowed a max of 5 patients and yourself ) 2.5 oz per patient so 15 oz total final product legally ( so if you have 72 plants ( your max ) ) you need to skirt the lines carefully when you dry because it would be a shame to be caught with more then you are allowed and you know as well as I do 1 outdoor plant will put you over the limit.
-On that same topic you need a reliable and legal way to disperses your product and the pharmacies will low ball you (150-225 an oz ) if they even want it ( you will be competing against indoor growers ) and will only buy small amounts when compared to what you would be producing.
-Growing is expensive in general ( you are cutting out the electricity of the lights which is a big chunk but Nutes and soil are expensive ) and growing outdoors puts you at a huge risk for pests that could ruin an entire crop causing you a total loss
-You will need a Lawyer on retainer, good ones are expensive
-biggest hurdle is the Cash nature of the business, you can't put that into the federal banks yet / pay income taxes on it. So be prepared to have 100,000's of basically illegal dollars and no safe or responsible place to put it. You could open your own pharmacy as a nonprofit and pay yourself a salary, but as it stands the pharmacies aren't legal people just don't fuck with them right now. So long story short you are operating in a VERY large gray area there is ALLOT of money to be made but the risk is still very real.
-Advice for someone new ( start small and grow big, don't cut yourself off at the knees taking on more than you are ready for, you could dig a very large financial hole ), so grow a small amount 5lb-10lbs and see how quickly you can get rid of it legally and go from there. Also keep a real taxed job for obvious reasons.