As I have been building my sandbox, I have realized I want the action to be largely player driven primarily by want of treasure (because I want a decent amount of dungeon and lair raiding). The things, it is really hard to find stuff for players to spend money on in 5E.
Does anyone know of any DMGuild or other 3rd party resources that develop a good economy for 5E -- from downtime business investment to training costs to benefits from carousing and so on? What I do not want is the primary money sink to be powering up (especially in the form of buying or making magic items).
I mentioned earlier: On Downtime and Demenses by Courtney Campbell is a good place to start.
I just gave my players a copy and said you can do any of these things. They are just starting to take advantage of it, but there are a lot of things one can do in the book during downtime.
1. Brag about their exploits for extra XP
2. Study an adventuring site / scout for bonuses to saves
3. HIre retainers and followers and sidekicks
4. Carousing and training (learning new skills)
5. Getting involved in power struggles
6. Building constructs vehicles, researching magic and lore and so on.
It has a version for both 5E and Basic / OSR. Its pretty comprehensive. I recommend checking it out.