This is a pretty bad idea, honestly.
Not only does it become really annoying to purchase any items for crafting absolutely anything (unless you can automatically pay through the bank), but it would be annoying to buy absolutely anything else.
Unless the money system is changed, and everything is paid through the bank, limiting the money you can carry in your wallet is nothing but a massive hassle.
And if it does come to the point where /everything/ can be paid through the bank, you may as well remove the wallet entirely.
I personally find this suggestion too excessive, as it means that every shop, as well as selling from your own shop, would have to be re-coded, so that the money was paid through the bank, instead of your wallet. It might be easy to do, or it might be a massive pain in the ass, but nonetheless, it's an unnecessary thing to do.