To add to this, The banking system has nothing to do with the current economy. The people who have lots of money have lots of money because they grinded hours a day for weeks/months.
Removing the banking system wouldn't help the economy and the loss of money made by players would be negligible.
+ If you want to think of something that helps the economy, the best things imo are things that are a mixture of expensive, temporary, popular, and rare. Take for example the Barrett.