Exalted uses a very abstract system for wealth, but the Masters of Jade sourcebook is one of the best systems for building a business empire. It's not the focus of the game, but it's good for inspiration, and can make for fun sessions.
Stars Without Number has an entire sourcebook dedicated to running merchant adventures in the form of Suns of Gold. It's probably the cheapest option overall, since one version of the SWN corebook is free, but be warned that it's based on second edition D&D and a combat-free run will make anyone playing a Warrior very unhappy.
edited 12th May '14 12:46:21 PM by CountDorku
Hm, thanks. I'll look over these. I might have to see what I can do about stripping character creation down to the bare minimum; I want to do whatever I can to discourage combat-optimized builds, and some of the people I'm probably going to be asking to play are relatively new players who have been burned repeatedly by games they spent time and effort getting ready for that fell apart before they got to play.
The comics equivalent of PTSD.
I'm thinking about running a game soon that involves little-to-no combat, and instead focuses on the acquisition of money.
What game provides the best systems for building an economy and trading goods?
The comics equivalent of PTSD.