| Warmongerer |
Remember that when converting gp to pp that platinum actually weighs less than gold. By that I mean 5000 gp in platinum weighs even less than one tenth of 5000 gp in gold. You can also have an equal value of silver and it would only weigh 5 not 10 times as much ( because silver is about half the mass of gold per mole). And an equal value in copper coins would only weigh 25 not 100 times as much because copper is about a quarter the mass of gold per mole.
*there is probably not that big of a difference in platinum to gold for most cases. There is only about a one gram difference per mole between the them.
** that one three oz gold coin would weigh approximately 9.5 g which would be about .05 moles of gold.
*** the above assume equal moles of the various metals in each respective coin