I want to have more bells

The title, i want to have lots of bells bc im tired of paying for things to get done like house upgrades and bridges, inclines etc, i dont mind grinding bells for items but the infrastructure spending bugs me so much!!! I know having lots of bells will prob ruin the game for me but i have a second account on that island and i want it to pay for everything infrastructure related while my other account just plays the game normally, grinding and decorating. So in conclusion, how can i get lots and lots of bells??? I’ve seen that treasure islands exist but im scared that i will have to wait in a line for a long time in order to enter one, what would you recommend?