(HRC) mystery battle royal final table setup help.

So i want to study FT stage in MBR on GG . Been looking around for how to set it up in HRC but can't find all info.
So far i got 18000 chips in play. Going to set up $10 MBR for easier maths.
Someone told me the average bounty should be $9 because rake is taken off bounty part of prize pool.
And i put in payouts for top 3 and minus one bounty from 1st as can't win your own bounty.
So top 3 should get $90 in prizes at %44 , %33 , %22 payouts minus one $9 bounty from first prize.
So payouts $31 , $30, $20.
And i put bounty mode KO with $9 per player.
Am i missing some stuff. Would like to get it right so got accurate calcs.