Ive always wished hardcoe tweaked your money a bit.

My ideal would be giving money weight, and measuring money in "Aprox. Value instead of caps.

Different money has different weights, like a bag full of bottlecaps would weigh considerably more than the same value in legion coins, pre war money or $NCR.

Legion coins could be buffed interms of value to balance the changes. Maybe even add some more types of legion coins like a one lower than Denarius and 1 or two in between out 2 existing coin types, and NCR notes for all existing US currency donominations ($1, $5, $10, $20, $50 and $100)

Carrying so many caps or coins could decrease stealth, because metal jingle jangle jingles.

Pre war money could be divided into different notes too,$1 Pre War Money, $5 Pre War Money, $10 PWM, $20 PWM, $50 PWM, $100 PWM.

Different traders could pay in different things,
Like NCR traders in $NCR, Legion Traders in coins, specific traders (Like Nellis and Brootherhood of Steel) could use Pre War Money, and neutral traders could use a mixture of the four (caps included)

Legion traders could refuse to accept $NCR and NCR traders could refuse coins, forcing you to exchange at a neutral trader or a casino.

Just an idea I've had

I agree only with the different traders trading exclusively in their faction's currency. The whole multiple currencies seems like it was something put in the game but undeveloped as a gameplay mechanic. Doing that and then having only NCR traders in NCR territory would really give a sense that you're stepping into a new territory when you go to visit a settlement occupied by Caeser's Legion or something.

How would one go about making a mod like this?