I'm using the provided openRCT2_calculator2.xlsx spreadsheet but there's an error in the calculation of the price. For Columns K5 and so on use this one:
=ABRUNDEN(ABRUNDEN((ABRUNDEN($E6*100*$H6*32/32768;0)+ABRUNDEN($F6*100*$I6*32/32768;0)+ABRUNDEN($G6*100*$J6*32/32768;0))*K$3;0)/5;1)-0,1