Outside of the hotel room in Twoson, there will be a man sitting at a table. Constantly speak to him (his response will change each time) until he decides to hand you $50 so you can leave him alone. It takes about 20 sessions of talking for him to fork it over, but it's well worth it, plus it'll make up for the night you spent at the hotel.
If you go into a room with a large amount or any amount of enemies in it, you can exit the room and re-enter it and the amount of enemies changes sometimes even taking them all out of that room. This can eliminate time consuming fights.
Note: This only works in the Super Famicom version of Earthbound(Mother 2).
In Mother 2, you could use the Exit Mouse in the Cave of the Past, which was never intended obviously, since the feature is missing in Earthbound.