It isn't exactly a bug but the message of profit/loss doesn't use the income modifier in the config file.
Edit: Same for items. The sell price doesn't multiply by the modifier.
Looking through the code, not all of the config income/expense modifiers are used.
The items expense part is only used for gang weapons and the item income is never used.
For the expense numbers, these are used:
training, movie_cost, goon_wages, matron_wages, consumables, item_cost, slave_cost, brothel_cost, brothel_support, advertising
These are not:
actress_wages, staff_wages, girl_support, bar_cost, casino_cost, bribes, fines
Income is even worse, only slave_sales is ever used.
The rest are not: extortion, brothel_work, street_work, movie_income, stripper_work, barmaid_work, item_sales, clinic_income, arena_income, farm_income
Most are actually 2 different variables, in cConfig and in cGoldBase, used the same way but not interacting with each other.
That is probably why they never got working.
Also, because I never change them, I never see them not changing.
I will start trying to incorporate them into the game.
They may not get in all at once or even the same one at the same time, but eventually they should do something.