Welcome to my secret message.
In the rules, it has the bonus scoring separate from the final sell-off. However, my son pointed out that the bonus scoring can actually be made easier: just add the count of a particular color of cube in the Council Chamber to the last market price of that color, and cash out your cubes.
Here's some simple math:
Bonus = Chamber cubes X player cubes
Selloff = Market price X player cubes
(Chamber cubes X player cubes) + (Market price X player cubes) is the same as (Chamber cubes + Market price) X player cubes.
Note that it's not "moving the market price marker over 1 space per cube," since the higher the price, the bigger the value jump between adjacent spaces.
Love the game! We did find it hard to remember to award the dividend cube after the excitement of the market adjustment.
Yup, I do the same thing! I just wrote the rules this way to avoid people mistakenly moving the price cube up on the price machine, since that could end up being incorrect for higher priced potions.