You would loose 3/4 of the Congregation, at least in our case! We only have 5 out of 70 main contributors( I know because I'm the Accounts Servant).
An Elder asked me recently; "Why do You think our Accounts have run out of money?". I said: "Only 2 Elders out of 7 contribute each month and in the past 2 years, only 1 of our MS out of 6 has. We rarely get Cash, we don't accept Cards, so I base my answer on the Checks we receive".
Our last 2 Local Needs talks have been about donating, those that contribute, just donated more.