When playing the game for the first time, watch the intro. It shows the character getting water from the well at the bottom of town. Well as soon as you begin the game, you can obtain unlimited water from that well. Oddly enough, this water can be sold at the shop right up the street for 5g a piece. 99 waters (the maximum that can be held at one time in your inventory) sells for 495g. This can be repeated infinitely.