Nemezis Optional Wealth Rules is a (free !) abstract tool that helps you to manage the lifestyle in downtime of your player characters. Of course, it is devised for the sci-fi environment of "Nemezis" but nothing prevents you from adapting it to your own universe. It is possible that, after an adventure, the heroes wish to settle down for a while, maybe in order to make some money (to buy a fortress, a vessel... ?).
If you don't want to use more detailed rules (as in Paizo Pathfinder's "Ultimate Campaign" or in the Game Master's Guide II for D&D 3.5), then this PdF is for you. It gives indications for "Purchase Rolls", very useful if you want to recknon the player's earnings on a very broad basis, not counting every single penny. As is tradition with Savage Worlds, cards are drawn to generate how well/poorly did your professional activity/business/estate fare last time. Perhaps this will throw a thread towards some new adventure...
These optional rules may not solve all your (players') money issues, but it can be definitely helpful between two adventures !
[4 of 5 Stars!]