This is exactly the right attitude in my opinion. Wherever there is money to be made, be it public or private sector, thieves will show up with big smiles and sharp suits on. Consequences are the only thing they understand, and prison sentences are the only true consequences for white collar crime (fines just become a cost of doing business, the only thing you can't get back is time).
The problem is that you have to know how often they get caught in order to decide the amount. For example, if they only get caught 1/4 of the time, the fine needs to be greater than four times the amount stolen to make a difference (force the expected value of the behavior below zero). In practice, it would probably need to be quite a bit higher than that since people who do this sort of thing are likely risk-takers/gamblers.
So there are then two things you have to guess at. First, how often they get caught (which is difficult, but not impossible to estimate) and second, how far below zero the expected financial payoff must be to change the behavior.
You also have to figure out what happens when they don't have the money (or the money is well-hidden). Do they just go into some kind of negotiated payment schedule like people who lose lawsuits? That might have no impact at all since their illegal earnings are likely to be hidden from authorities anyway (or can be if needed).
This is why I favor prison, because a prison sentence is much harder to "cheat" or nullify. No one lives forever, so prison is like taking a small chunk of a precious commodity away from someone. Additionally, if you are a big earner, prison is actually worse for you in some ways because you generally lose your income while incarcerated. This means that even very rich people or people who hide their wealth from the authorities can be punished effectively with prison time.
On principle, I'm opposed to prison being used for anything but violent offenders where there are no other choices to safely contain them - prison includes a very real possibility of rape, assault, and so on.
The administrative penalties could simply be scaled to be much scarier without needing to go that far.
Personal financial liability (piercing the corporate veil) with limited negotiation of terms (and since personal credit is usually factored into business credit, that bankruptcy will greatly impact your ability to do business), administrative dissolution of business, very very large fines, and so on.
I completely agree with you that rape and assault in prisons is a terrible problem. I still think prison is a better solution, but I definitely agree that throwing anyone in the prisons we have currently (at least in the US) is probably immoral.
You have a very small chance of being caught if you ride the subway without a ticket. If you are caught some countries will work out what to fine you by multiplying the chance of being caught by the price of the ticket you didn't buy. So if they check your ticket once every 100 times you catch a train the fine for not having a ticket will be more than 100 times the cost of the ticket. That way not buying a ticket works out more expensive than buying one.
If you actually want to deter this kind of crime you need to fine the people who are caught the amount of money they stole multiplied by the number of people who don't get caught. So you should probably be thinking 20 or 30 times the amount stolen.
Of course such large fines might take entire industries down with them so you're unlikely to ever see corporate crime punished as excessively as it should be.
The train example is very informative because if you don't price the fine high enough you encourage people not to buy tickets. There actually was a mob-run "insurance" plan for train riders in India. The fine was about 20x the ticket price, but you would only be asked to show your ticket about every 100-200 rides. So you could buy half priced tickets from the mob and then they would reimburse you for any fines you paid while riding with their ticket.
