You'll have MLS dues, Supra key fees, Errors and Omissions insurance, state association dues, etc. All of this probably totals about $2,000 a year. When we started we were with a smaller local broker, and we ended up switching to Keller Williams (national company, locally owned franchises). KW has been great because our monthly broker fees are less and their training and technology is far superior. Although, I will say I miss a bit of the small business family feel. If you have any questions about KW, feel free to email me.
As others have mentioned, be careful jumping in full time from the start. It takes a little bit to get going. Also the further along you are the more of a referral base you'll have. So, sometimes a slow transition starting part time is better, unless money in the first 6-12 months is not much of a concern.