If you're using Savage Worlds, why not use a Savage Worlds style mechanism for wealth. Have each character have an extra Ability Score: Wealth. To buy something you'd make a normal ability check to see if you could afford it. Perhaps saying that ordinary gear is free, and only extrordinary items require a roll. You could impose a -2 or -4 for really big ticket item. Your "richies" could be one-time bonuses or re-rolls to a wealth roll.
I'd probably disallow the "Wild Die" for wealth rolls.
Everyone would start with a d4 in wealth. So, if you wanted to buy a car or a motor boat, or something like that, you'd need to roll a 4 to do so. If you took the "Poor" flaw, you'd have a d4-2 on rolls. If you took the "Rich" advantage, you'd start with a d8 in wealth (and so forth with super-rich and noble advantages). You could increase your wealth by spending an advance (once per tier). If you got money somehow and didn't spend advances, you obviously didn't invest your money properly and wasted it on liquor and blow.