I thought of an interesting idea while I was falling asleep in my English class today.
What if at the bank you can access a, "Safe Deposit Box" where you can deposit weaponry and other items safely for a fee? At the same time, you can buy your own safe and put your things in it as well, for the cost of the safe of course. With different types of safes costing different amounts of money and being more difficult to break into.
The benefit could be that as you put more things in your safe deposit box, the more fees rack up, and buying a safe could save you money over time. Additionally, it could let criminals commit a high risk bank robbery and loot people's belongings, which is another reason to buy a safe.
Additionally, it gives criminals a reason to break into people's homes because the only other valuable object (within my knowledge, of course) is your car.
This could serve as the, "Inventory" feature you were thinking about a while ago. Unless you already created one, in which case disregard this entire post.