Didn't open my own shop. Built a team inside a flat-fee brokerage instead.
I spent most of last year convinced the answer was my own brokerage. Ran the costs, talked to three broker owners, and ended up doing something less interesting that worked better.
I moved to a flat-fee firm, $299 a file plus $89 a month, no percentage split. Then I hired the two agents I'd already been handing overflow leads to and put them on a team agreement inside that brokerage. They pay the brokerage its flat fee, and my team takes 40% of their side on leads I generate, 15% on deals they source themselves.
Last twelve months: 41 closed sides across the three of us. Average commission per side $7,900, so $324k gross. Their combined 24 sides generated about $61k to me after the brokerage fees came out. My own 17 sides cost me roughly $6,200 total in brokerage fees instead of the $40k a percentage split would have taken.
What nearly broke it was compliance. A flat-fee shop gives you a broker of record and not much else, and after the buyer agreement changes I was writing my own workflow for when the agreement gets signed, what goes in it, and how compensation gets documented. I paid an attorney in my state to review my forms and it was the best $1,800 I spent, because form requirements differ by state and I wasn't going to guess.
What I'd keep: renting the license instead of owning it. I get most of the economics of a small brokerage with none of the E&O and supervision exposure sitting on my name.