This is a simple guide on how to get a million caps.
1. Get caps.
Craft and sell, lift boxes, do quests, steal, trade, whatever.
2. Make a bank account.
3. Wait.
It's as simple as that, thanks to the wonders of compound interest.
Assuming that banks give 2.5% daily:
If you started with 1 000 caps - you will have a million at day 281
If you started with 10 000 caps - you will have a million at day 188
If you started with 100 000 caps - you will have a million at day 95
If you started with 500 000 caps - you will have a million at day 30
From that point your caps will double every 30 days.
Ain't life beautifully?