The concept of wealth in D20 modern is that modern finances are really quite complex. I would first recommend reading the postings by the game designers at
This link and that should explain the concept.
Another rule of thumb would be to have your characters buy all their gear first, including any shares in a spaceship, (check
my postings on this idea)
Once they are done with that I would divvy up the shares in the ship, multiply that by 0.1 (to represent the
available equity) and add any remaining cash to that total.
Convert this number on a 1:1 ratio for Dollar$ and consult the wealth chart in the D20 Modern rules. This will produce a wealth number from which you can work.
What this also works out to is a wealth somewhere between 20 and 35 for most PCs with a starship. While incredibly high for most modern games you will find that the players dip into that quite deeply to make any speculative cargo purchases.
If you want to get even more abstract just give the players a +1 wealth bonus for every roll on the cash table over Cr1000 (This would include during term resolution and mustering out) and another +1 Wealth bonus for every term in a service that has cash bonuses (IIRC Belter, Merchant, Mercenary, Professional, Rogue). After that if they muster out with a ship take 1% of the equity in a ship i.e. a new Far Trader is worth MCr67.384 and a PC with one award of ship on the merchant tables owns the down payment, 20%, with 40 years remaining on the ship. Which all works out to MCr13.4768 in equity. This means that the PC has about KCr134.768 in available credit, cash, and trade favors. Convert that KCr134 on the table and you have the wealth level of the character.
Say it real fast and $134,000 sounds like a lot of money, until all the other expenses of ship ownership are factored in. If you are going to speculate on cargo that money will go fast. So make the PCs take a few ranks in K:Interstellar Law and P:Free Trader, every level progression have them make a profession check against a DC of 15, if they succeed give them a +1 wealth bonus. Another thing to realize is that at Wealth levels above 16 it is pretty much a given that any purchase will only result in hit against your wealth if the purchase is over DC15 in value. This means that night vision goggles, air/rafts, and rifles all ‘cost’ about the same to a rich character. It also means that the ACR you took off the pirate who tried to capture your ship will only gain you +1 wealth when you try to sell it.
Play around with it, I still am. But I find that it makes the game go faster and keeps the gritty details of high finance out of my player’s eyes, letting them focus on the wonderful game I am spinning for them (like a spider’s web….henh henh henh!)
::Edited thanks to TJoneslo::