hi
i think when u r tabulating yr budget shld put ave of $50 like that then u will knw roughly how much $$ u need to top up
example :if amara package =750 for sunday x 30 table =$22,500
est any pow = 50pax10x30 =$15,000
the top up = $7,500 ( excluing beer,wine& liquar)
something like that, then u can roughly guage how mcuh u hv to save.
to be kiasu a bit save $10,000 that will be anypow ave $42 per person, should always get the worse scenairo ;P