Whine noise is coming from the 2006 Nissan Maxima Engine

Last week I bought 2006 Nissan Maxima from Ed-Martin Acura. Now whenever I am
pressing the gas paddle a high pitched whine noise is coming from the engine. I took it
to Nissan Service Center and they said my Timing Chain need to be replaced. They
even said if the timing chain snaps I have to replace the engine. Can anyone one tell
me if this is really timing chain issue ? Can timing chain really snaps? I thought timing
chain can not snap. What will be the adverse effect if I do not change the timing belt
now. I just bought the car and don't have money to replace the timing belt now. I would
like to wait for another six months.