It varies based on how practices are structured and if they own any equipment/real estate.
My current group does not own anything so buy-in was minimal-10-15K...If a group owns stuff (particularly in a desirable place to live) then you may need to take out a loan.
In general to make 99th% income, one will be reading 99th% volume which is soul-crushing (unless you have the ability to disconnect yourself from your dictations). Funny how some of these high-volume groups over high end vacation time. At face value seems great but it simply means that you are reading that much more when you actually do work