As someone noted, municipal water supply quality varies from town to town.
Where I live, the water doesn't need tons of chlorine or filtration. In fact, I worry more about what I'm drinking if I'm in an older building that may have lead in the pipes than if I'm in a new building.
Since my house is relatively new, I put a big water dish in the snake cages that comes straight from the tap.
I'd say if you think there's too much chlorine, chloramine or fluoride in your towns water, invest in a 5 gallon bucket and use that to "age" your water.
I would only buy bottled water if there is high levels of bacteria from the tap.
Good luck.
Doug T