Opening your own brokerage costs

I am looking to make a swap. I love where I am but I have a high cap and high split. I am currently taking the brokers course and considering stepping out into my own brokerage. What things should I think a about as far as costs go? I want to make a financially wise decision. I have a building I can use rent-free. So far I know E & O insurance, utilities, licensing fees, business license. I don't plan to take many agents under my wing, so this move would mainly be only for me. I am not concerned with trainings, CRMS and etc. as I have a plan for those things.

Am I losing my mind for considering making this switch?