$1000 notes for sale?

Hey. So recently my grandfather gotten into an accident and needs money for surgery, problem is he lives in Malaysia and does not have insurance due to his age. Relatives right now aren't working or are moving house and don't have the funds to help pay the bills, so the burden falls onto my father and my first aunt.

As, my father was depositing money to transfer overseas I noticed he still had a bit of $1000 notes saved up. I know these notes aren't in circulation anymore so I thought we could sell them for a profit and gain more financial ease. But I am unsure as to if this is possible. So my question right now is, is it possible to sell these notes? And if so what kinda price is reasonable?

Much appreciated.