By opening the Menu often out in the field, you won't encounter enemies as often as usual. This is a bug in the game that was removed in future releases such as Mother 1+2.
This won't fix the American health system, but at least this will help make the in-game visits to the doctor cost less.
The doctor charges you one half of your cash-on-hand. Just deposit most-or all-of your money to make him charge you very little to none.
After Loid joins your party, return to the Sweet's Factory where you got your first Bottle Rocket. Now the trash can disperses infinite bottle rockets.
In the Northern area of Magicant you can find a red weed sitting in the middle of a bunch of green weeds. "Check" the red weed and you will recieve the Red Weed. Now bring the Red Weed to the Fountain in the North West portion of Magiciant and "Use" the Red Weed. The Red Weed will change into a Magic Herb.
Do this as many times as you like to recieve an unlimited number of Magic Herbs.