Just an idea for a series of skills.
It would require Better Learning 3 and Bureaucratic Arts 2 for Economic Skill 1. This would reduce prices at vendors by a small amount.
Economic Skill 2 would need Economic Skill 1 and Better Learning 4. This would give further vendor reductions and also give more rerolls on a Rube trade.
Finally Economic Skill 3 would need Economic Skill 2. This would increase the daily coin limit that you can collect.