Finally cracked open my collection that's been boxed away, I have some dupes, your thoughts needed

So over the past year Ive bought some stuff that I didn't realize I already have. Examples being ff3 and Castlevania iv for the snes.. not super expensive but definitely not the cheapest.

What do you guys do with your dupes? I'm torn, idk if I wanna keep the dupes or sell them and try to put the money back into another purchase.

One part of me wants to keep them in case one of them stop working or something, but if something crazy like that happens honestly I just could re-buy. Don't know if there's something I'm not thinking about. Thanks