PAUL wrote:
i have a friend who also had extra money
but doesn't want to invest on time for proper caring and maintenance....
eventually all his fishes died...

true, fishkeeping is a costly hobby, and often costs more time than money, indeed.
if i was to spent some extra money i'd buy a big canister with a couple of gallons of waterconditioner or Prime.
The bigger canisters are a whole lot cheaper in comparison to smaller bottles, for the same amount and you will need quite a supply to keep up with weekly waterchanges.
I remember buying my first couple of gallons of waterconditioner and thinking they'd last forever.
But with the amount of water i change in all my tanks every week, forever was not feisable.