You use money to pay for miscellaneous things in the story (buying food/supplies, bribing a character for information, paying for transportation to your next destination, whatever). But more importantly, you use money to buy and upgrade your equipment (weapons, armors, etc).
By default, all characters start with $100.00 in “personal savings”. You usually get more money by completing missions and quests, picking the pockets of fallen enemies, finding treasure, and so on. You can also get money and/or income from certain races and classes.
Click on the Finances tab at the bottom of your character sheet.
Detailed Transaction (Cash Received and Spent)

Here’s where you’ll keep track of all the money you earn and spend.
If you have any “extra cash” from your class or race, put it here under “cash received (+)”.
Whenever you earn, steal, receive, or otherwise find/get money, add it under “cash received (+)”. Include a brief description too, in case you go back later and wonder what it was from.
Whenever you spend, lose, or otherwise are parted from your money, write it under “cash spent (-)” as a negative number.
“Balance” is a running total of all your income and all your expenses entered here.
Important: If you buy yourself any weapons, armors, or other equipment, be sure to include them here as “cash spent (-)”.
Recurring Income Per Level

If you have any recurring, on-going income sources, keep track of them here. Examples might include a job salary, blackmail money received, royalties, interest earned on investments, etc.
Remember: Every time you level up, look at your “Total Income” and write that in as cash received (+) under “Detailed Transactions”.
Recurring Expenses Per Level

If you have any recurring, on-going bills or other expenses, keep track of them here. Examples might include rent, blackmail money paid, subscriptions, interest paid on debts, etc.
Remember: Every time you level up, look at your “Total Expenses” and write that in as cash spent (-) under “Detailed Transactions”.
Investments

You can invest some or all of your money to earn interest, every time you level up!
Decide how much you want to invest. Write that for Total Invested. This is money being spent to purchase an investment (such as stocks, bonds, certificate of deposit, real estate — whatever you want it to be). So be sure to include this as “cash spent (-)” under Detailed Transactions.
Now, roll a D20. This determines your Interest Rate.
Note: If your Financial skill is 20 or higher, you may roll the D20 twice and pick the better roll. If your Financial skill is 30 or higher, you may roll three times and pick the best roll, and so on.
Also note: there’s no maximum interest rate you can earn on investments. Certain classes are experts in finance and investing, and may offer you a bonus to any investment rolls.
You may invest up to 100% of your available cash.
Your Income Per Level automatically calculates your earned interest. You earn this interest as free money every time you level up.
Now that you’ve purchased your investment and calculated the interest earned, go to “Recurring Income Per Level” and record this information. You will begin earning that interest starting next level. You will continue to earn interest for as long as your money remains invested.
You can get your invested money back at any time. But as soon as you do, you’ll no longer continue earning any additional interest.
If you want to add to a current investment (perhaps you’re reinvesting your interest), you may do so at any time and keep the same interest rate.
You may roll for a new interest rate once per level. If you do, you may keep the old interest rate or accept the new one.
Loans

You can also borrow money. But if you do, you’ll have to pay interest on your debt, every time you level up.
Decide how much you want to borrow. Write that for Total Borrowed. This is money you will receive from the bank or other lending institution. So be sure to include this as an “cash received (+)” under Detailed Transactions.
Now, roll a D20. This determines your Interest Rate.
Note: If your Financial skill is 20 or higher, you may roll the D20 twice and pick the better roll. If your Financial skill is 30 or higher, you may roll three times and pick the best roll, and so on.
Also note: the lowest possible interest rate is 1%.
You may borrow up to $100 x your Financial total.
Your Expense Per Level automatically calculates the interest you owe on the debt. You pay this interest every time you level up.
Now that you’ve borrowed some money and calculated the interest payment, go to “Recurring Expenses Per Level” and record this information. You will begin paying that interest starting next level. You will continue to pay interest for as long as you continue to hold that debt. This is an “interest-only” loan. If you want to pay down the debt itself, you’ll have to make additional payments.
You may try to “refinance” and get a new interest rate once per level. If you do, you may keep the old interest rate or accept the new one.
Bankruptcy?
If you level up and owe more money than you have (due to greater expenses than income), you may end up going into bankruptcy.
First, try to pay the shortage. Get back any investments you may have made (losing their future interest earnings in the process). Still not enough or didn’t make any investments? You can sell your equipment and inventory items at 50% of their normal cost. If that’s still not enough, you can take out an emergency loan (one time, ever, per game) at 25% interest to cover what you need (regardless of your Financial skill).
If you level up again and still don’t have enough to cover what you owe, and you already took out an emergency loan this game and have no personal items left to sell, you will go into bankruptcy.
Going bankrupt isn’t so bad. You lose all personal items and equipment, including your car, house, and/or any other assets or investments you might somehow still have. But all your loans/debts are also removed, giving you a fresh financial start.
Unfortunately, you won’t be able to borrow any more money again this game. You’ll also take a permanent -5 per level penalty to your Financial skill that cannot be healed.
If for some reason you simply refuse to pay on your debts, whether or not you can afford to, the Story Master can also force you into bankruptcy.
In short: if you borrow money, make sure you can afford it and intend to pay it. But if for some reason you can’t or don’t, there’ll be some problems, but it’s not the end of the world.