I want to buy a pet fish tommorow. I need something cheap..and that will survive in a small/medium fish bowl..i was thinking about getting one betta fish..Would I need to get a heater and filter and all that or could i just change the water. I only have like $25 so i need a fish that is low maintenance..I think 1 fish, fishbowl, gravel, food, and those little net things should cost below 25 right??any help would be great?