Offline and MT (Euro Truck Simulator 2)

Hello everyone, my friend has a problem, after playing multiplayer, he went alone and he got one and a half billion money, so playing is not at all interesting and wrong, he has only 1 driver on 1 truck and so he could not make money ... QUESTION!!! How to twist money so that it is not enough? Maybe what to write in the file or how to decide at all I will be very grateful for the feedback