Most money glitches were patched within the brainstorm update from calamity mod, but I found one that still works!
All you need is the architect (from AlchemistNPClite) and the painter to be on a house in the jungle, this way, the architect will be as happy as he possibly can.
Then, buy a windmill for 1 gold and 50 silver, then place it down and mine it up again, you'll notice that it'll be now selling for 2 gold and some silver!
The money will increase exponentially and you can abuse this as much as you want.